Decide whether the italicized word is being used as a determiner or a pronoun.
this is a big mess.
determiner
pronoun

Pronoun

Explanation:

In the sentence - This is a big mess. - 'this' is used as a pronoun, to be exact a demonstrative pronoun.

A demonstrative pronoun is a pronoun that is used to point at something specific within a sentence. It can be items in space or time.

These pronouns are This, That (for singular), These and Those (for plural).

This / These are used for singular items that are nearby. That / Those are used for multiple items that are not near us.

Examples:

This is my cat. - we can point at it, the cat is near us.

That is a plane. - the plane is not near us, so we use 'that'.

These are my favorite toys. - we point at many toys, and they are near us.

Those are my classmates. - we point at the classmates, they are not near.

Why 'this' is not a determiner in the sentence - This is a big mess.

A determiner is a word that introduces a noun. It always comes before a noun, not after or without a noun near!

This car is bad.

These pies look delicious.

I hope it helped you :)

.the definitions

.the number of syllables in the word

.the pronunciation of the word

.the parts of speech

.the foreign translations