Sentence Types

There are essentially four sentence types in written English, with many variations on appearance. Let’s look at these types and a few examples.

The Simple Sentence The Compound Sentence
The Complex Sentence The Compound-Complex Sentence

The Simple Sentence

This type of sentence has one independent clause. Many modifiers can be added to the independent clause, but there will only be one subject-verb combination. Modifiers may include adjectives and adverbs, phrases, participles, time expressions, and so on. The sentence may appear long and complicated, but in essence it is the independent clause alone that expresses this sentence’s main idea.

NB: A sentence that does not contain an independent clause is a sentence fragment.

Ex: I decided to go to the mall. (sub – I; verb – decided; obj – to go to the mall) to the mall is technically an adverbial complement to the verb go (go where?), but the entire phrase makes up the object.

Last week I decided to go to the mall.

Last week, my friend Lisa and I decided to go to the mall.

Last week, my friend Lisa and I decided to go to the mall to do some window shopping.

Last week, my friend Lisa and I, feeling bored at home, decided to go to the mall to do some window shopping and see the new displays.

Last week, my friend Lisa and I, feeling bored at home, decided to go to the mall to do some window shopping and see the new displays set up for the Christmas holiday shopping season.

All of these sentences are simple in that there is only the one independent clause that contains one subject and one verb (I/Lisa and I, went). All the other words and phrases are modifiers that provide extra information, but that are not necessary. The reason they are not necessary is that the function of this sentence is to express the idea that I decided to go to the mall (sentences 3–6 have the added subject Lisa and I, which does not affect the sentence’s main idea other than to add Lisa as a participant in the action. Lisa creates a compound subject, but this compound subject is still one subject that leaves us with an independent clause.)



So what are the modifiers?

Last week– time expression

feeling bored— adverbial participle (phrase) = because we were feeling bored (the participle is not a clause as it does not include a subject-verb combination, although this combination is understood.)

to do some window shopping— infinitive phrase used as a complement to the verb went. This phrase adds the information of why we went to the mall.

and— conjunction, though not used here to add another independent clause, but rather to add another complement to the verb went. It adds another reason that Lisa and I went (in other words, it adds a second reason in the list of reasons we went, i.e. we went because of reason 1 and reason 2).

see the new displays— another infinitive phrase. The infinitive to is unnecessary here because the conjunction and suggests a parallel structure whereby to do and to see are both being used to show a reason for the verb went. Because both verbs are being used in the same way, we can eliminate the ‘extra’ to.

set up for the Christmas holiday seasonset up is a reduced adjective clause (that were set up); for the Christmas holiday season is a prepositional phrase (for) as complement to set up, and a noun phrase (the Christmas holiday season) as object to preposition for. The subject/pronoun that and the verb were can be eliminated (This is discussed in the adjective clause section and the reduced clauses section.) What is important to realize here is that without a subject-verb combination, all you have is a phrase (in this case an adjective participle).



Let’s look at this sentence another way:

Feeling bored at home, my friend Lisa and I went to the mall last week to see the new displays set up for the Christmas holiday shopping season and to do some window shopping.

This sentence is rearranged, yet carries the same meaning, and is still a simple sentence. The only difference is that now to see the new displays set up for the Christmas holiday shopping season is the main complement to the verb went; we also need the second to with the new infinitive because it is too far removed from the verb it complements (went).
Here are a few more examples of simple sentences:

  • One of my favourite childhood memories is of going to my grandparents’ house to celebrate Thanksgiving with my parents and all of my relatives, especially my cousins from the States.
  • Taking the express commuter train to work every day is a good way for many people to save not only valuable time, but also a lot of money.

(Taking the train is a good way to save time and money—this is the sentence stripped down to bare essentials)

  • Not being the type to be told what to do, Jack struggled under the commanding leadership style of his new boss.
  • Go! (subject—you, verb—go)

The Compound Sentence

This sentence type contains at least two independent clauses joined by a coordinating conjunction (and, but, or, so, yet) or a semicolon (;). As with the simple sentence, it may have many or few modifiers. Having a sentence with more than three independent clauses is possible; however, it is not recommended because it risks becoming a run-on sentence, which is a sentence that contains too many ideas and either no conjunction or not enough punctuation; this can make the main focus of the sentence unclear). In simpler terms, a run-on sentence is a sentence that needs to be split into two or more sentences, or joined by a conjunction/semicolon in order to be complete and grammatically correct.

It is important to realize that there is a major difference between a compound sentence and a compound predicate. Both use a coordinating conjunction, but the compound predicate does not have a second independent clause but is rather connecting two elements (phrases, words) under one verb.

Ex: Many case managers fail to utilize proper standards in their initial investigations or take into account extenuating circumstances as expressed by the client.

In this sentence there is only one independent clause, making this a simple sentence. Compound predicates is discussed in the section on conjunctions.



Furthermore, it is important to realize the function of the coordinating conjunction in these sentences. Each conjunction has a particular function in terms of how it relates the two independent clauses. The conjunction and, for instance, indicates the addition of an idea in the second clause to that presented in the first clause. The conjunction but indicates a contrast, whereby the second clause presents information that is opposite or in contrast to that contained in the first clause.

Let’s look at a couple of examples:

1- Management first needs to assess all the available information, and only then should a committee be established to plan a response.

2- We must first decide our best course of action, but we should not be hasty in coming to an agreement on this.

In sentence 1, the first independent clause is management first needs to assess all the available information. The second independent clause is a committee should be established to plan a response. The inversion in the second clause occurs because of the adverb only (see inversions). The second clause is joined by the conjunction and, suggesting that we are adding (consequent) information to the first clause.

In sentence 2, the first independent clause is we must first decide our best course of action. The second independent clause is we should not be hasty. The first clause suggests that we need to take action. This generally implies a need to be quick. The second clause contradicts this idea of quickness, using the conjunction but to suggest that we should not be hasty. What is important to recognize here is that a contrast does not need to be a direct negative/positive relationship, but rather a relationship of contrast. The sentence can be rewritten (We must first decide our best course of action, but we should take our time in coming to an agreement on this.) in such a way as to have a positive verb in each clause yet still require the contrasting conjunction but.

When trying to understand what the main idea of the entire sentence is, it is generally a good approach to focus on the first independent clause, though this is not always true.

For a more comprehensive look at coordinating conjunctions and comma usage, see here.

Compound Sentence Examples:

And/;

Tom loves to travel and he especially enjoys going on adventure tours to exotic locales.

Please read the details of the contract carefully; contact Sheryl, our legal aide, with any questions or concerns regarding your obligations.

But

The professor provided her students with the exam questions, but she warned them not to take that gesture as a sign of an easy test; on the contrary, she strongly advised them to use the questions as a study aid, not a free pass. (Notice that the semicolon can be used before a linking word or phrase regardless of the relationship of one clause to another)

Henry really wanted to go to the party at the frat house but he had to study for an

exam on the following day.

Or

One possibility is to call a taxi to pick you up and take you to the airport, or you can splurge a little and hire an airport limo.

The landlord told the tenants to vacate the apartment by the end of the week or he would be left with no choice but to call the police to forcibly remove them.



Examples of simple sentences that include a coordinating conjunction:

We need to be vigilant in our approach, but not at the expense of human relationships.

It is crucial to administer the vaccine right away and check for vital signs frequently thereafter.

Call or send us a text at this number for more information.

The Complex Sentence

These sentences include an independent clause and at least one dependent (subordinate) clause. dependent clauses come in three forms—noun, adjective, or adverb clause. What distinguishes these clauses from independent ones is the use of a subordinating conjunction or relative pronoun or adverb, such as that, which, who, because, although, and so on. A dependent clause has a particular function to serve in the sentence: a noun clause acts as subject or object within a clause (including the independent clause); an adjective clause acts as an adjective to a noun, just as a normal adjective does, though it uses a subject and verb combination to do so; an adverb clause has a direct relationship with the independent clause, such as time (before, when, while, etc.), reason (because, since, etc.), condition (if, whether, etc.), contrast (although, though, whereas, etc.), and others.

A complex sentence, as mentioned, can have more than one subordinate clause, though you should take care not to make your sentences too long, with too many clauses, because you run the risk of having a run-on sentence.  In complex sentences, moreover, punctuation plays a key role in the construction of the sentence, which means that it is quite easy to make mistakes that will make it difficult for the reader to follow the train of thought presented.




Here are some examples of complex sentences:

Although you have probably covered much of the information listed here in your earlier English grammar classes, it is nevertheless a good idea to review it as you may uncover some new ideas that will help you as you advance.  

Read the above sentence carefully. How many clauses can you identify?

There are in fact four (5) clauses.

Although you have probably covered much of the information listed here – adverb clause (contrast) (listed here is a participle phrase, which is a reduced adjective clause (that is listed here))

it is a good idea to review it – independent clause (the main idea of the sentence)

as you may uncover new ideas – adverb clause (reason)

that will help you – adjective clause (modifying the noun ideas)

as you advance – adverb clause (time)

Notice as well that the clauses have been pared down, with the ‘extra’ words and phrases removed.

in your earlier English grammar classes and nevertheless are a prepositional phrase complement and a transitional word, respectively. They add information, flow, and style, but are essentially unnecessary. They are modifiers.

Of the five hundred or so applicants that we interviewed, we feel that there is a small pool of roughly fifteen whom we would feel confident in asking to return for a more comprehensive analysis that includes a case study taken from a real-world situation.

Sentences such as this should not be frightening or confusing. Just as with any sentence in English, the key to understanding this sentence lies in identifying the independent clause and then recognizing how the rest of the words and phrases add modifications to it.

How many clauses can you identify? What is the independent clause?

Of the five hundred or so applicants – introductory prepositional phrase

that we interviewed – adjective clause (modifies applicants)

we feel – subject and verb of independent clause

that there is a small pool of roughly fifteen (applicants) – noun clause as object of feel

whom we would feel confident in asking to return – identifying adjective clause (modifies fifteen (applicants))

for a more comprehensive analysis – prepositional phrase complement

that includes a case study – adjective clause (modifies analysis)

taken from a real-world  situation – participle phrase (reduced adjective clause modifying case study)

Still unsure? The independent clause in this sentence is we feel. Essentially, the main idea of this sentence is that we feel something, or we have a feeling about something. that there is a small pool of roughly fifteen whom we would feel confident in asking to return, is a necessary completion to the independent clause in terms of completing the meaning of the sentence. It is important to understand that there is a difference between the main idea and the overall meaning of the main sentence. The complete idea, therefore, is We feel that there is a small pool of roughly fifteen (applicants) whom we would feel confident in asking to return. This is the focus of the entire sentence with other elements added in as modifiers to supply more information.



Here are a few more examples of complex sentences:

  • If you take into account the number of possible outcomes of this experiment, while also considering that there may be many variables that might further complicate the final conclusions we hope to reach, relying on this method might, in the long run, prove worthless.

Independent clause = relying on this method might prove worthless

  • After they had conducted a long global search for the right specimen, the lab technicians at last found just the right subject.  Independent clause = the lab technicians found the right subject
  • What nobody seems to fully comprehend is why she resigned from such a great position only to pursue a futile dream of success in the arts. This one is a little tricky; here we have a noun clause as subject and another noun clause as complement. Although we have two subordinate clauses, they combine to make the entire sentence an independent clause. Though this may suggest a simple sentence, the fact that it contains subordinate clauses makes it a complex sentence.

What nobody seems to fully comprehend – noun clause as subject of the entire sentence

 is – main verb of the entire sentence

why she resigned from such a great position – noun clause as subject complement

only to pursue a futile dream of success in the arts – adverbial phrase as complement (to resigned)

Written another way, this sentence means No one knows why she resigned.

The Compound-Complex Sentence

These sentences contain two independent clauses joined by a coordinating conjunction, as well as at least one dependent clause. As with the compound sentences we discussed earlier, be sure that there are two full clauses (including subject and verb) and not a compound predicate. Likewise, be sure that the subordinating conjunction is properly placed such that it 1) modifies an adjective appropriately (adjective clause), or 2) functions as subject or object/complement appropriately (noun clause), or 3) has a very clear relationship to one of the independent clauses as necessary (adverb clause). It is possible to join a subordinate clause to either or both independent clauses, or conversely, to join two clauses under the umbrella of one subordinate conjunction, but be sure not to have an overly long sentence that loses its focus.



Here are some examples of this type of sentence:

While we appreciate the tremendous efforts of our staff during these difficult times, we feel obligated to inform you, our loyal customers, that we will no longer be able to operate on a 24-hour schedule, and we therefore ask for your patience and understanding as we restructure our schedule to try to serve you as best we can. 

After Kate finishes sweeping the floor and Jason mops it, be sure to place all the furniture back in its place, and call me when it’s done so that I can have a final look.

In the first sentence we have six clauses and a few phrases (in parentheses, below). There are two independent clauses, three adverb clauses, and one noun clause as complement. This sentence can be split in two by placing a period before the second independent clause and starting a new sentence from We therefore…. This is a question of preference.

While we appreciate the tremendous efforts of our staff (during these difficult times) –– adverb clause

we feel obligated to inform you (, our loyal customers,) – independent clause

that we will no longer be able to operate (on a 24-hour schedule) – noun clause-complement (inform about what?)

we therefore ask (for your patience and understanding) –independent clause

as we restructure our schedule (to try to serve you) – adverb clause

as best (as) we can. – adverb clause (This is a colloquialism. Removing the second as is grammatically incorrect, but widely accepted.) 

In the second sentence we have four clauses: two adverb clauses and two independent clauses.

After Kate finishes sweeping the floor and (after) Jason mops it – adverb clauses (Though there are two, they are considered part of the same subordinating conjunction and are therefore a compound.)

be sure to place all the furniture back in its place – independent clause

and call me when it’s done – independent clause

so that I can have a final look. – adverb clause

Notice that you can join two dependent clauses with a conjunction, yet this would not be a compound sentence, but rather a compound adverbial clause:

After Kate finishes sweeping the floor and Jason mops it, they can go home. – complex sentence, not compound-complex.
Here are a few more examples:

  • I called Jack to congratulate him on his recent promotion, but he was so busy that he couldn’t take my call.
  • Once the steel is sufficiently heated, it can be wrought into the desired shape and the edges can then be sharpened.
  • One may submit the request in person, or, if distance is an issue, one may fax the request to the overseer’s office.
  • Ms. Holland prepared all the documents as per the court’s instructions, yet she was unable to advance the case because a clerk at the court office mishandled certain parts of those documents.

Dependent Clauses