A sentence is a group of words that contains an idea. A sentence always begins with a capital letter and ends with a full stop. It must have a subject and a complete verb. Examples:
The boy ran. “The boy” is the subject and “ran” is the finite verb.
The bottle broke. “The bottle” is the subject and “broke” is the finite verb.
A sentence can give information, ask for information, express an emotion, and give an order or instruction.
A sentence can be short, with one idea. Example: Joseph feeds the dog. This kind of sentence is a simple sentence.
It can also contain more than one idea. Examples: Joseph feeds the dog and gives it water. He takes it for a walk before it has eaten, after he comes back from school. These are compound and complex sentences, and are joined by conjunctions.