I eat apples.

Hi Ibo Both are correct, but in different contexts. The first one is true in general. The second one, is true when you're referring to an specific apple. We we use "The" we are pointing to that specific thing. For example, I like the ice cream(the one on table).

Both of these are correct, it depends on the context. If you are speaking about apples in general we don't use the article "the" - "I eat apples". This means I am speaking about what I usually eat apples. If you are speaking about specific apples (those apples there, on the table), or apples that have already been mentioned.- "I eat the apples".

"The” can be used before either a singular or plural noun.

I think while using the plural, the article is missed as you express a general idea. So, the first sentence is correct