WHO is?

Spanish and English are not the same languages and you don't make the sentences in the same way.
In Spanish you don't have to write out or say WHO is doing something because the verb is written in a special way and you understand it anyway.
But in English you have to write or say WHO is doing somethin (el sujeto).

Es alto = It is tall, he is tall.

Juan va a mi clase y me gusta porque es alto. = Juan goes to my class and I like him because he is tall.

I like this story because it is very nice.

I like you because you are kind.

He likes me because I am funny.

If you just write "He likes me because am funny" you miss something and the sentence is incomplete.

Now write a comment with that kind of phrase.