"Most human beings i) What grammatical name is given
to this expression as it is used in
the passage?
ii) What is its function?

This question is incomplete. Here's the complete question.

"Most human beings use at least one and sometimes two or more languages."

i) What grammatical name is given to this expression as it is used in the passage?

ii) What is its function?

i) Noun Phrase

ii) The subject of the verb, "use".

Explanation:

A noun phrase is a word or combination of words that includes a noun, and its function is to be the subject, object, or prepositional object in a sentence. When a noun phrase is found at the beginning of the sentence, it´s most likely working as the subject of the verb. In such a case, the noun phrase is often found before the verb or verb phrase.

In this example, the phrase "Most human beings" is a noun phrase functioning as the subject of the verb "use".

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