Substitution in English grammar is when a word, phrase, or clause in a sentence is replaced by a different word or phrase (e.g. one, do, this) in order to avoid repeating the previously used word.
In these examples of substitution, the word/phrase in blue has been replaced later by the word in red:
Here are some common words and phrases that we use for substitution in English grammar.
We often use the words yes and no instead of long sequences of other words. These are clausal substitutions as they are replacing whole clauses:
We use words such as here and there as substitution in English grammar to replace details about place. In other words, to replace adverbials of place:
In order to replace details about time (adverbials of time), we use words such as then and at that time:
These are often called nominal substitutions as they are replacing nouns in a sentence:
This is often referred to as a verbal substitution as it is an auxiliary verb used to replace verbs or verb phrases:
We also sometimes combine do with so and the same to make a substitution:
These two words are commonly used to replace clauses, and they are therefore clausal substitutions.
We use this and that for substitution in English grammar in order to refer to longer pieces of text that can't usually be related to a specific part of the sentence as in the examples above.
They would be classed as clausal substitutions as they are replacing whole clauses:
This and that are often interchangeable in substitution as in the first example, but we use that to disassociate ourselves from something or someone as in the second example.