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.



Why are the examples above for complex and compound sentences not using commas?
This has become a serious issue in my class yesterday as I couldn't find a reason to explain it.

Hello isafdar,

As far as I can tell, none of the example sentences above should have a comma in it. Could you tell us one that you think is a missing a comma and where you think it should be? Perhaps we've missed something or at least we can explain how it's punctuated.

All the best,
The LearnEnglish Team

Hi guys, I have two questions:
1. Can two independent clauses in a sentence contain different numbers of verb "e.g., "I love him, and he will be leaving tomorrow."(independent clause A has just a verb (love) while B has 3 (will be leaving).
2. Can a subordinate clause and an independent clause in the same sentence contain different number of verbs e.g., " I left him at the mall, because I had to go and get my hair fixed."

Hello Timmosky,

The answer to question 1 is yes, that's no problem at all. Your example is correct. Your second sentence is also correct, though it seems to me both clauses have subjects of the same number (first person singular). But in any case they could be subjects with different numbers and it would still be fine.

All the best,
The LearnEnglish Team

Can gerunds take objects.e.g., "Eating potato chips is fun." And "learning Mandarin is difficult." Are "Potato chips" and "Mandarin" objects in those sentences.

Hello Tim,

Yes, gerunds can have direct objects. Gerunds function as nouns but have a verbal root and retain certain verbal characteristics, such as having a direct object and being capable of being modified by adverbs.


Best wishes,


The LearnEnglish Team

Is there a difference in meaning when you change the position of a subordinate conjunction in any sentence. E.g., "we had finished cooking when he arrived" and "when he arrived, we had finished cooking." if they mean the same thing, can the position of subordinate clauses be changed across all tense forms (present, past, continuous, perfect)

Hello Timmosky,

These two mean the same thing. In general, subordinate clauses can be moved around like this, but I'm afraid I can't say if that's always true -- there are just too many possibilities to think of for me to be able to verify that with confidence. If you can think of any specific ones you want to ask about, feel free to do so.

All the best,
The LearnEnglish Team

Hi Kirk
Can you also help me out regarding when to use who and whom in relative clauses. I am not fully understanding when and why I should use whom. Thank you.

Hi Alyson,

'Whom' is actually slowly disappearing in modern English. We can use 'whom' when the relative pronoun is an object (which is what Timmosky's comment is describing). However, it is much more common to use 'who' for both subject and object nowadays.


Best wishes,


The LearnEnglish Team