Pronombres de objeto indirecto y verbo gustar
An indirect object is the 'to/for whom' of a sentence. 'I give the book to mom' — 'mom' is the indirect object. Spanish has a separate set of pronouns for these (mostly the same as direct), plus a special verb gustar that ALWAYS uses an indirect object.
Indirect object pronouns
me (to me), te (to you), le (to him/her/you formal), nos (to us), os (to you all, Spain), les (to them / to you formal plural). Match the direct object pronouns except in the 3rd person: 'to him/her/them' is le and les, no gender distinction.
Where they go
Right before the conjugated verb — same as direct objects. Te escribo una carta = I'm writing you a letter. Le doy el libro a Pablo = I give the book to Pablo. Often the pronoun AND the noun appear together (le doy a Pablo is fine — for clarity).
Gustar — flipped logic
English 'I like the book' looks normal. Spanish me gusta el libro is grammatically the opposite. The subject is el libro (the thing being liked). The me is the indirect object. Literally: 'the book is pleasing to me'.
Conjugating gustar
Practically, gustar shows up in two forms: gusta (one thing being liked) and gustan (multiple things). Me gusta el café (I like coffee). Me gustan los libros (I like books). Te gusta hablar (you like talking — infinitive is always singular, even multiple stacked together).
Different liker — different pronoun
I like → me gusta(n). You like → te gusta(n). He/she likes → le gusta(n). We like → nos gusta(n). You all (informal) → os gusta(n). They / you formal plural → les gusta(n). The verbs encantar (to love), interesar (to find interesting), and doler (to hurt) work the same way.
Clarifying with 'a mí, a ti, a Pablo…'
For emphasis or clarity, add a + pronoun/name at the start: A mí me gusta el café, pero a Pablo le gusta el té. Here a mí / a Pablo doubles up — it doesn't replace the indirect pronoun. The me, le stay.
