A sentence is made up of words. Words make sentences.
But is it enough to know that words make sentences? Or should we know the features of the English words like their forms (if any), their functions and their arrangement in sentences.
Let’s take the example of a sentence to understand this:
A bird flies.
In this sentence the first word is a. It can’t change its form. It remains unchanged, in whatever sentence we use it.
The second one is ‘bird‘. It has two forms: bird and birds. But we can’t use birds here because it can’t be used with a.
The third word is flies. It again can change its form to become fly, flew, flown, flying, flies. But with A bird we can use either flies or flew. No other form is possible. The sentence may be either
A bird flies
Or
A bird flew
So in this sentence the first word, a, can’t change its form. But the other two, bird & flies, can change their forms.
Similarly we can’t arrange the words of the sentence, A BIRD FLIES, the way we like.
For example, we can’t say:
a flies bird
or
bird a flies
or
flies a bird
But then how do we know which words can change their forms and which cannot? And which form of a word should be used where? And then how to arrange words to make sentences?
It is for this reason that the words of English have been divided into nine word classes which are commonly known as Parts of Speech. The words in English are unlimited but Parts of Speech are limited. These Parts of Speech such as nouns, verbs, adjectives, pronouns, articles, determiners, prepositions, conjunctions have been divided on the basis of their forms, if any, and functions.
If we understand the features of the Parts of Speech, then it is easier for us to use words in sentences.
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