the word 'someone' is a pronoun and refers to an unspecified individual person. This word can be used as a subject or object of a sentence depending on the context. For example, someone could be the subject of a sentence when talking about the individual 'Someone spilled their coffee.' It could also be used as an object of a sentence when talking about the person being addressed in the sentence 'I want to talk to someone.'
Someone is going to the store today.
I need to talk to someone about this issue.
It's nice to see someone doing the right thing.
it is important to note that the word 'someone' is an indefinite pronoun, so be sure not to mistakenly interchange it with a definite pronoun like 'he' or 'she'.