I like apples? He likes apples.对吗？

错了吧~~an后面是单数

对的
I would like to eat an apples . 不应该有s的

I like apples? He likes apples.这两句是对的~-~I would like to eat an apples 是错的，可以改成I would like to eat apples

i like apples, 意思是我喜欢吃苹果，在这里，apple不是特指某一个苹果。
He likes apples？好像不是这么说吧？一般都是I/He like apples.

I would like to eat an apples, 我觉得加不加“S”都可以，我见过有不加的。

I like apples. 主语I+谓语动词like+宾语apples
He likes apples. 主语He+谓语动词like[第三人称单数形势 谓语动词要加S 所以出现 likes]

I'd like to eat an apple. 主语+would[情态动词]+谓语动词+宾语
like + to do or doing
like+名词、动名词、TO DO 不定式
or I'd like to eat apples.

印错了，勇敢告诉老师印错了