A ti no te gustaría que te dijeran...
You wouldn't like it if they told you...
con quién tienes que andar.
who you have to hang out with.
Captions 1-2, Tu Rock es Votar - Comercial de TVPlay Caption
As per our previous discussion of the verb gustar, the phrase above states:
"You wouldn’t like it if they told you who you have to hang out with."
But what does the addition of A ti at the beginning do for the phrase? It simply adds emphasis to the "you," the translation would be same even if it wasn't there.
[Side note: remember we talked about andar's various meanings outside of the obvious "to walk"? The phrase above demonstrates yet another, "to hang out / pal around."]
Él le hizo daño a mucha gente.
He did harm to many people.
-¿Qué daño te hizo a ti, mamá?
-What harm did he do to you, Mom?
Caption 11, Yago - 10 EnfrentamientosPlay Caption
I like you.
A mi me gustas.
I like you. ("I" emphasized.)
A mí me gusta cambiar las sábanas cada semana.
I like to change the sheets every week. ("I" emphasized.)
Caption 21, Ana Carolina - Arreglando el dormitorioPlay Caption
Besides adding emphasis, this type of construction can also clarify about whom you are talking.
Le gusta bailar.
He likes to dance.
A Juan le gusta bailar.
Juan likes to dance.
No mires a tu compañero, a ti te estoy preguntando.
Don't look at your buddy, I'm asking you.