1. I like apples.

2. I like an apple.
3. I like the apple.
4. I like one apple.
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In #1, the word 'apples' is in generic use. What about #2? Does #2 mean #4? Or an apple in #2 is a generic noun?
In #3, the apple means the specific apple, doesn't it? Can 'the apple' be a generic noun in #3?

1 is a general referral to apples.

The others seem to be referring to specific apples, depending on context.

In sentence #1, "apples" is used in a generic sense, referring to apples in general. It does not specify any particular apple.

In sentence #2, "an apple" refers to one apple in a non-specific sense. It could refer to any apple, without specifying a particular one. Therefore, sentence #2 does not mean the same as sentence #4. Sentence #4 specifies a specific number (one) and refers to a singular apple.

In sentence #3, "the apple" refers to a specific apple, implying that there is a particular apple in context that is being referred to. It could be pointing to an apple that was previously mentioned or is known to both the speaker and the listener. Therefore, "the apple" in sentence #3 is not a generic noun.

To summarize:
- Sentence #1: "apples" is in a generic sense, referring to apples in general.
- Sentence #2: "an apple" refers to one apple, but it does not specify a particular apple.
- Sentence #3: "the apple" refers to a specific apple, not a generic noun.
- Sentence #4: "one apple" specifies a particular number (one) and refers to a singular apple.