why i need to add "le" before "gusta" ?

Question

Why should i say "le gusta"? tnx

Answer 1

You would only use le if the person whom the subject pleased was him, her, or you formal. In Spanish's intransitive expression of English transitive "to like" sentence, the indirect object tells who likes the sentence's subject.

A ella le gusta Emilio. She likes Emilio. (Emilio is pleasing to her).

A él le gusto [yo]. He likes me. (I am pleasing to him)

A usted le gusta el idioma español. You like the Spanish language. (Spanish is pleasing to you.)

In English the le could also refer to it, but unless you are pesonifying an object (or animal) Spanish doesn't usually attribute feeling to an object so gustar isn't used with inanimate objects as the indirect object..

A ello le gusta el frío. (It likes the cold)

A la flor le gusta la luz del sol. The flower likes the sunlight. (personification of the flower).