Teacher: Look at this question.
Student: It is one of the most difficult.I tried to solve but couldn’t.I need your help.

In the above dialogues It & This have been used differently and leaving you with a question when to use this and it because the usage seems to be indistinguishable but these pronouns are different from each other in many ways.

Main Difference – It vs This

It and this are another two words that confuse many English learners. Although both these words can be considered as pronouns, there is a difference in their grammar. The main difference between it and this is that it is a third person singular personal pronoun whereas this is a demonstrative adjective and pronoun. The functions and meaning of these two words also change due to the differences in their grammatical categories. In addition, it is mainly used with animals, and non-living things whereas this can be used to refer to people as well.

This article explains,

It – Grammar, Meaning and Usage

It is the third person singular personal pronoun. It is often used to refer to animals or non-living things. It can be used as a subject and an object.

Example: The dog was taken to the vet since it looked ill.

Example: The waiter brought a tray with two glasses on it.

It is also used as the subject of sentences about time, weather, and distance.

Example: It’s half past nine.

Example: It rained last night.

It is also used as the subject when there is no identifiable doer or actor.

Example: It is important to learn about history.

Example: It is impossible to enter the castle without being seen.

It can also emphasize a part of a sentence.

Example: It is the course which helped me to improve my soft skills.

Example: It is the institute which organise indoor competitions, survey sessions and weekend workshops.

This – Grammar, Meaning and Usage

This is a demonstrative adjective and a pronoun. Since it and this is mostly confused due to their functions as pronouns, we’d specifically look at this as a pronoun in this article.

This is used to identify a specific person or thing close by or being indicated or experienced

Example: This is the Spoken English Institute I told you about.

Example: Is this Public Speaking Session taking place?

This is used to introduce someone or something

Example: This is my mentor Mr.Reuben Singh.

Example: This is the best Institute to learn soft skills.

It vs This – Confusion in Usage

It’s my mother

This is my mother

Most people are confused about the difference between sentences like the above examples. What is the exact difference between them? The main difference between them is that it identifies the person, and this introduces the person.

If you are introducing your mother to your friends, you can say “this is my mother.” But, if you get a call from your mother when you are with your friends, and you want to identify the caller, you’ll say ‘it’s my mother.’

Gender

It is used with non-living things and animals. (neuter gender)

This can be used with female, male and neuter genders.

Identify vs Introduce

It is used to identify a person.

This is used to introduce a person.

Time, weather and distance

It can be used as the subject in statements about time, weather, and distance.

This cannot be used in statements about time, weather, and distance.