Simple sentences are formed in English containing an independent clause that forms a grammatically complete action, event or idea. A simple sentence should have a complete noun and verb relationship with any necessary additional information. To make writing more interesting, and lively, English speakers do not onlyuse simple sentences, however. Simple sentences on their own can seem immature, or develop a stop-start rhythm.
We also have combinations of clauses, which can form compound or complex sentences – for longer sentences with more than one verb. These can be used to add variety, and flow, to writing. They can also express more complicated, and connected, ideas. It is important to develop an understanding for these different types of sentence structure, to write in a more complex, varied, and natural manner.
Simple Sentences
A simple sentence contains a subject and a verb, connected to express a complete grammatical structure. For example:
- The student read her book.
- We were playing in the park.
- It is cold outside.
- William and Julie have eaten all our cake.
These are all simple sentences as they contain one complete clause. Note that we are discussing a simple sentence specifically – just because the sentence is simple does not mean the tenses, subjects or additional information are simple. The components of the sentences can contain phrases with multiple words, such as prepositional phrases (such as in the park), compound nouns (such as William and Julie) and different verb aspects (such as were playing or have eaten).
Compound Sentences
Compound sentences are where more than one independent clause is connected as one grammatical unit.
- I ate my lunch, and I went to school.
This example is essentially two simple sentences (I ate my lunch. / I went to school.) joined by a conjunction. The conjunctions used for compound sentences include words such as and, but, for, yet, so, nor, and or. These different conjunctions are called co-ordinating conjunctions. They combine two independent clauses, and can represent a relationship between the clauses of a compound sentence, but do not make the clauses dependent on each other. They can, however, represent different relationships between the independent clauses:
- She studied all night, so she was late for the exam.
- She studied all night, but she was late for the exam.
The first sentence shows she was late because she studied hard (using so), while the second sentence shows she was late in spite of studying hard (using but, suggesting a contrast).
The separate ideas of a compound sentence can exist independently if you remove the conjunction:
- The dog fetched the ball and he brought it back.
- The dog fetched the ball. He brought it back.
When you list more than one independent clause, for instance in a sequence of events, it is not necessary to connect each one with a conjunction. In such an example, you can separate independent clauses with commas.
- I walked into town, I met with my friends and I bought a new computer.
When the subject is the same in different independent clauses (as with this example), it does not necessarily need to be repeated.
- I walked into town, met with my friends and bought a new computer.
The independent clauses in compound sentences are often ordered according to time, when showing a listed sequence of actions.
- I went to the shop, and I bought a bag of fruit, then I came home.
However, if the order of events is not important, and we are not showing cause and effect, then the order of the independent clauses can be flexible.
- On our holiday, we sunbathed on the beach, we went to many restaurants and we swam in the sea.
- On our holiday, we swam in the sea, we sunbathed on the beach and we went to many restaurants.
Complex Sentences
In a complex sentence, an independent clause is joined to one or more dependent clauses. These are also connected by conjunctions, but they are subordinating conjunctions that create a dependent connection between the clauses. Dependent clauses lack information that would make them a complete idea, for example:
- when the tide comes in.
- since I left the UK.
Subordinating conjunctions that create dependent clauses include because, when, since, if, after, and although, and relative pronouns such as that, who and which (which form, more specifically, relative clauses).
- I cried when I watched that movie.
- The teacher groaned because the class were bring so noisy.
- He helped the man who was waiting to cross the road.
As complex sentences are joined in a dependent way, there is no comma between the clauses when the independent clause comes first. However, the dependent clause can come at the beginning of the sentence, separated by a comma:
- Because of the bad weather, we decided to stay at home.
- After the game was over, the players were very tired.
The dependent clause can be placed first like this to show sequencing of time, or to build up to the independent clause. This can be done for emphasis, tension or merely to explain things in a logical order.
- Since the park was closed down, the children have nowhere to play.
- Although she liked the movie, she was frustrated by the journey home.
There is no correct order of clauses in complex sentences. You can experiment with them, and add greater variety to your writing.
Beyond Simple, Compound and Complex Sentences
When you can easily identify clauses and the way they are connected in simple, compound and complex sentences, you can build longer and complicated sentences that combine different simple, compound and complex sentence structure. For example, two sentences joined as a compound can form an independent or dependent clause in a complex sentence:
- Because the council refused to pay for the building’s repairs, and winter was closing in, the weather was bad and the roof was leaking.
Simple building blocks can lead to complex ideas. As long as you are aware of the simple building blocks, picking out subjects and verbs, and understand their relationships, you can form increasingly elegant, and varied, ideas.
Peter is arriving late
“I go to school with them” – complex or compound or simple?
Hi Nish, it’s simple as there is only one verb clause.
Their progress was slow because they were tired . It is compound or complex
Hi Misha, it is complex because ‘because’ makes the clause dependent.
Hi, is this a compound sentence or not??
I was really hungry but I had to wait until lunch time
As I’ve said before it would be best if you show your own thinking to help understanding – given the information in the article, why would you consider it to be compound or not?
You may go home as soon as your work is done ,is it compound or complex
Hi Fatima, it is complex as the second clause is dependent.
Time and tide wait for none, is it a simple or compound sentence
Hi Namrata, that is a simple sentence – the conjunction is used to create a compound noun ‘Time and tide’, which acts as the subject.
Kani buh.
6. It is Monday but Fe did not go to work.
This is a _____________________
Compound or complex
We generally treat “but” as a regular conjunction (not subordinating), making this compound rather than complex.
If you have the 2 sentences: Peter is late today. He usually arrives on time. Why would joining them into “Although Peter is late today, he usually arrives on time” be incorrect?
Hi Sonia, it’s not incorrect (I’m not sure why you think so, I hope there’s not something in the article to suggest so?) – but I’d note it does slightly change the emphasis of the sentence. Your two sentences separately are neutral, and could be interpreted as surprised, upset or otherwise, while linking the sentences with “Although” tells us you are forgiving of his behaviour.
the man is poor but honest. is it simple or compound?
Simple, as there is only one verb – ‘but’ merely links two adjectives that modify the same noun using the same verb.
Sara bought fruits and vegetables..Is it simple or compound
Hi Ahaana,
That is a simple sentence as the ‘and’ only joins two nouns, not two clauses (i.e. there is only verb).
Hi Phil,
My understanding is that there are four main sentence constructions (simple, compound, complex, and compound-complex), and that there are four main functions that sentences perform – these functions are declarative, interrogative, exclamatory, imperative.
Your article above deals mainly with declarative sentences (whether it be simple, compound, complex, and compound-complex). My question concerns interrogative sentences (i.e. questions), and whether there are such things as simple interrogative sentences, compound interrogative sentences, complex interrogative sentences and compound-complex interrogative sentences, and if indeed there are, could you kindly list down examples of each?
Also, to stretch it a little further, how about exclamatory and imperative – are there simple/compound/complex/compound-complex exclamatory and imperative sentences?
Thanks!
Regards,
Tim
Hi Tim, the simple answer would be that yes, absolutely you could have all four varieties used in all four types of sentences – but the complication there would be that they might not necessarily connect with another clause in the same form (so, for example, an imperative statement might be made complex with a declarative subordinate clause). I can produce some examples of all these, though not right now – I’ll add it to my lists and perhaps do it as a separate article or include it here!
Hi Phil, hmm i see. But how about an example of what you said, that is “imperative statement made complex with a declarative subordinate clause”?
Hi Tim,
Certainly – it could be as simple as a command with additional detail in the form of a clause: “Keep the window closed while it’s raining!”
Hi
Is the statement “Sara bought.” a complete and meaningful sentence?
Thanks
Hi Mazen,
Apologies for the slow response – no it is not a complete sentence in this case because ‘bought’ requires an object. (I.e. ‘What was bought?’) This makes it a transitive verb. Only intransitive verbs, requiring no object, can form a complete sentence with just a subject. You can learn more about the differences here.
The students and the teachers met in the auditorium. simple or complex?
Hi Mugesh, this is simple because the conjunction is part of the noun phrase, not connecting two verb clauses.
“Fatimah made a cake. I gave her a chocolate yesterday.”
How to make the sentence into complex sentence?
As it says in the article – to create a complex sentence you need to connect the two clauses with a subordinating conjunction such as because, when, since, if, after, and although.
Lata and suman cooked and served people through the day. Is this sentence compound or complex?
Perhaps it would be most useful if you explained why you think it would be compound or complex? As that would be the best way to learn.
I hope that you will study for your test on Friday. Is the sentence simple or complex?
I ate my peas so that I could eat my dessert. Is this sentence compound or complex?
Both of these are complex as they include dependent clauses.
For future comments: if you’d like to check your understanding of an example sentence type, please let me know what type you think it is/your reasoning, and I can tell you if it’s right or not. The information is given in this article for learners to help themselves, after all.
Is ‘Fury as Covid-riddled Northumbrian visits Downing Street’ a noun-phrase or a complex sentence?
Good question – that’s a truncated sentence, really, the result being a sentence that doesn’t stick to the rules so doesn’t fit the typical classifications. It’s because we remove words from headlines for newspapers and such, as I’ve covered in this article on headline grammar rules. If we expanded the sentence to be grammatically correct, it would be something like “[There is] fury as Covid-riddled Northumbrian visits Downing Street”, which would be complex, but in its current form I’d sooner describe it as a headline than try to label it as a particular type of sentence.
You should overlook his fault as it would be an act of generosity on your part. (what is it simple, complex, compound, or compound-complex?
As I’ve said in a comment above, I’d encourage you attempt this yourself from the information in the article; what do you think it should be?
Hi, Mr. Phil.
Is ” Yesterday we went shopping but didn’t buy anything” a simple or compound sentence?
Hi Osman, that would be compound as you have two separate verbs, even if they share the same subject.