Sentences in English language

                      A sentence is a group of words that makes complete sense, contains a main verb, and begins with a capital letter. Sentences are used:

To make statements:

I took some money out of the bank.     The shop stays open until 9 p.m.

To ask questions or make requests:

Can I help you?   Could you open the door?

To give orders:

Stop arguing! Come here at once!

To express exclamations:

You’re driving too fast! It’s so cold!

Sentence or not?

                     The examples in the section above all show well-formed sentences. None of the following examples are proper sentences: 

‘Ham and eggs. And onions.’

Too much information!

‘Not at all, Joe.’

Which Rob shook

If it ever became public

                   The first three are not sentences because they do not contain a verb: they would be acceptable in informal speaking and writing, because they are easy to understand, but it's not a good idea to use such constructions in formal situations. 

                   The last two are not proper sentences because they do not contain a main verb or make sense on their own (they are in fact subordinate clauses). They need an additional clause so as to form a complete sentence and be understood.

Simple sentence 

                   A simple sentence normally contains one statement (known as a main clause). For example: 

The train should be here soon.

His father worked as a journalist.

Compound sentence 

                  A compound sentence contains two or more clauses of equal status (or main clauses), which are normally joined by a conjunction such as and or but. For example: 

Joe became bored with teaching              and        he looked for a new career.

[Main clause]                              [Conjunction]              [Main clause] 

Boxers can be very friendly dogs              but         they need to be trained.

[Main clause]                              [Conjunction]           [Main clause]

Complex sentence

               A complex sentence is also made up of clauses, but in this case the clauses are not equally balanced. They contain a main clause and one or more subordinate clauses. For example: 

The story would make headlines              if it ever became public.

[Main clause]                                    [Subordinate clause]

He took up the project again      as soon as he felt well enough.

[Main clause]                                   [Subordinate clause]