Language stuff - types of sentence

Sentences function in different sorts of ways, and we can classify them accordingly. The most obvious type is declarative - this conveys information:

• You are looking at the cat in the basket.

However, by reorganising the elements of the sentence, we can find the other sentence types. An interrogative sentence (question) is one which requests information.

• Are you looking at the cat in the basket?

An imperative sentence (command) is one where the subject of the sentence is being instructed to do something.

• Look at the cat in the basket.

Another class of sentence is exclamatory. Here, the sentence is intended to convey emotion through emphasis - so:

• Awww! Look at the cat in the basket!

does not function as an imperative, although the words are the same as the previous example.

Word order and punctuation aren't sufficient to determine the type of sentence. For example, parents might say to their children:

• Are you going to tidy up the floor?

in a way which acted as a command, rather than a question. Similarly, a declarative sentence can be used to ask a question through intonation. This might be represented in writing using a question mark, but the word order would be as for the first example above:

• You are looking at the cat in the basket?

We can also distinguish major sentences from minor sentences. A minor sentence is an irregular sentence, in that it doesn't contain a finite verb (a process). These have various roles - here are some examples.

• Yes.
• Wow!
• Hello?

Wikipedia notes that sentences consisting of a single word are called word sentences, and the words in these sentences are called sentence words.