ABSTRACT
Pronouns are a closed word class and their number is quite small. The traditional definition is that they ‘take the place of nouns’, hence their name. However, there are two problems with this definition. First, many pronouns are not replacing anything, for instance:
Somebody must know the answer.
It is raining.
Here somebody and it are not replacing any noun, and it is difficult to think of nouns that could take their place. Other examples of this regarding it are discussed in A11.