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 :)

heylo !

explanation:

i decided to stay late in the laboratory to continue my experiment with the lightbulb. at midnight, thomas edison opened the door and saw all the stuff he was working on. the lightbulb, film and the transmitter. as he walks in an idea hits him on how the lightbulb would work. he would have to change a few wires around to get it to light up. when he did change the wires around it worked so he decided to write a telegraph to his friend to tell him about his success.   as he was packing up he grabbed the telegraph and walked to his home. he told his wife about the success and the next morning mailed the telegraph.