Which of the following statements is not correct with reference to English grammar?
1
We can use 'it's' and 'it is' interchangeably.
2
Pronouns are the words that can grammatically replace nouns.
3
Auxiliary verbs, when present, conform to the tense, mood, voice, number of subject etc.
4
When we use more than one adjectives, the adjective of colour comes before adjective of opinion.