sentence structure


Simple sentences:

A simple sentence has only one clause:

The children were laughing.
John wanted a new bicycle.
All the girls are learning English.

Compound sentences:

A compound sentence has two or more clauses:

(We stayed behind) and (finished the job)
(We stayed behind) and (finished the job), then (we went home)

The clauses in a compound sentence are joined by co-ordinating conjunctions:

John shouted and everybody waved.
We looked everywhere but we couldn’t find him.
They are coming by car so they should be here soon.

The common coordinating conjunctions are:

and – but – or – nor – so – then – yet

Complex sentences:

A complex sentence has a main clause and one or more adverbial clauses. Adverbial clauses usually come after the main clause:

Her father died when she was very young
Her father died (main clause)
when (subordinating conjunction)
she was very young (adverbial clause)

She had a difficult childhood because her father died when she was very young.
She had a difficult childhood (main clause)
because (subordinating conjunction)
her father died (adverbial clause)
when (subordinating conjunction)
she was very young (adverbial clause).

Some subordinate clauses can come in front of the main clause:

Although a few snakes are dangerous most of them are quite harmless
Although (subordinating conjunction)
some snakes are dangerous (adverbial clause)
most of them are harmless (main clause).

A sentence can contain both subordinate and coordinate clauses:

Although she has always lived in France, she speaks fluent English because her mother was American and her father was Nigerian
Although (subordinating conjunction)
she has always lived in France (adverbial clause),
she speaks fluent English (main clause)
because (subordinating conjunction)
her mother was American (adverbial clause)
and (coordinating conjunction)
her father was Nigerian (adverbial clause).

There are seven types of adverbial clauses:

  Common conjunctions
Contrast clauses  although; though; even though; while;
Reason clauses because; since; as
Place clauses where; wherever; everywhere
Purpose clauses so that; so; because + want
Result clauses so that; so … that; such … that
Time clauses when; before; after; since; while; as; as soon as; by the time; until
Conditional clauses  if; unless; provided (that); as long as

Complete the sentences with conjunctions

Match conjunctions to functions



Dear LearnEnglish Team,
What is the big difference between coordinating and subordinating conjunctions? In other words, what is the importance to know, for example, "for" is a coordinative or subordinative?
Please also tell me why "for" is considered to be a coordinative while "because" and "since" are subordinating conjunctions?
Best regards,

I have problem with " As well As ", I want to know if it is a subordinate or coordinate?
I have seen on Wikipedia that in one part it introduces " As.....As " as correlative conjunctions which have the role of coordinating conjunctions, but in another part , "As far As" and " As Long As" have been taken as subordinating conjunctions ! Do they mean " IF" (as far as and as long as) if so, can they be taken as coordinating conjunction with another meaning?
But still confused about " As well As" !
if they are too many questions and you are not able to answer them here I will be very grateful to know just about " as well as"

Thanks a lot

Hello Mohsen.k77,

I'm afraid there are too many questions there, each of which would require quite a long explanation! 'As well as' is a co-ordinating conjunction, but in some contexts it can function also as a subordinating conjunction. See here for more information.

The area is a complex one and goes beyond our role here, which is helping learners with their ability to use English, and into language analysis/linguistics. You can find many forums and sites devoted to these areas, such as this one. A search for 'as well as conjunction' will provide many such links.

Best wishes,


The LearnEnglish Team

Hi Dear Peter,

thanks for your answer and help and thanks for introducing useful sites.

just if possible could you please give me two examples that in one of them " as well as" is coordinating and in another one is subordinating?

Best Wishes,


Hie! may you please help know. What is the question tag here "He hadn't seen that movie before". Is it "had he?" or "did he?"

Hello Lamastry,

'had he' is the correct question tag here. See our Question tags page for more.

All the best,
The LearnEnglish Team

Hello Sir
Can we use simple past without mentioning time expression? if so, which of these sentences is correct?
1. I wrote a letter.
2. I've written a letter.

Hello Bamiri,

I already answered this question – please do not post questions more than once.

All the best,
The LearnEnglish Team