Sentence Types

1. Types of clause

A clause can be defined as a group of words containing a verb.

There are two types of clause: main (or independent) and subordinate (or dependent). The following sentence contains one clause and is referred to as a simple sentence:
e.g. University students should make good use of their time.

If you combine two (or more) main clauses, you create a compound sentence.
e.g. University students should make good use of their time and equip themselves for the future.
You can check if these clauses are main clauses by checking whether the subject and clause make a complete and sensible sentence. 'University students should make good use of their time' is a complete sentence, and so is 'University students should equip themselves for the future', therefore these are both main clauses.

If you combine one (or more) main clause with one (or more) subordinate clause, you create a complex sentence:
e.g. University students should make good use of their time because not every teenager has this opportunity.
You can check if a clause is a subordinate clause because it will not make a complete and sensible sentence when combined with the subject, for example, 'University students not every teenager has this opportunity.' is not sensible, as it has two main subjects, and English sentences usually have only one.

2. Coordination and subordination

You can say that two clauses have a relationship of coordination if they are both independent and equally important. Words like and, but and or are commonly used to join them. For example:

* Chris majors in Accountancy and is a member of the university football team.
* Sam wanted to study law but was rejected by the university he applied to.
* You can register in person at the counter or you can do so on-line.

You can say that two clauses have a relationship of subordination if one is a main clause and the other a subordinate clause. The subordinate clause, which cannot stand on its own, gives information about the main clause. Words like because, if, that and some wh-words are commonly used to join them. Subordinate clauses can come before, after, or inside the main clause. For example:

* Many students opt for practical subjects at university because they believe that these courses offer better career prospects.
* If you want to improve your proficiency in English, you can visit the CILL when you are free.
* Students who have overseas study experience are usually more mature because they have learnt to become independent and open-minded.