Life is full of choices, so I must learn to make good ones. In this phrase "life" and "I" are nouns but is "ones" considered a noun also because is used as number or no??

"Life" is a noun, but "I" is a pronoun. The word "one" is a pronoun, too.

http://grammar.ccc.commnet.edu/grammar/pronouns1.htm >>> http://grammar.ccc.commnet.edu/grammar/one.htm

There's another noun in there, though, that you missed. Can you find it?

Yes, in the phrase "Life is full of choices, so I must learn to make good ones," "ones" is also considered a noun. In this context, it is used as a pronoun that refers to the noun "choices."

To determine whether "ones" is considered a noun, you can identify its role in the sentence and examine its grammatical characteristics. In this case, "ones" is used as the object of the verb "make." It represents a specific set of choices being referred to in the sentence.

The word "ones" is classified as a pronoun because it is used to replace a noun (in this case, "choices") to avoid repetition. It functions similarly to other pronouns like "it," "he," or "she." In this sentence, "ones" is used to refer to the choices being discussed – it specifically suggests making good choices.