Sí y sí que (uso enfático)

Question

I'm trying to figure out when it's okay to use a plain "sí" as intensifier and when it needs to be "sí que". Here are some examples:

Ella sí vendrá.

Éste sí que me gusta.

Lo que sí aprendió fue a bailar.

Hombre, ¡sí que puede bailar!

Is there a rule or is it a matter of personal preference? Are they interchangeable, e.g. "ella sí vendrá" = "ella sí que vendrá", "lo que sí (verb)" = "lo que sí que (verb)" or there's more to it? Thanks and have a wonderful day.

Answer 1

It will depend on the kind of sentence you're dealing with, let's see:

Ella vendrá: She's coming

Ella sí vendrá: she IS coming

Ella sí que vendrá: Rest assured she's coming.

About "lo que sí", you use it just like that to emphasize whatever comes next:

Lo que sí no sabemos es si vendrá mañana o pasado.

Thanks, much appreciated! :) - Manity, Mar 3, 2015