I wanted to make a quick note about the verb Saber, which means to know, but to know in terms of knowing information or knowing how to do something — as opposed to the verb Conocer, which means to know also, but in terms of being familiar with a place, or knowing a person, or meeting a person (Yo conocí a mi novia en 2004 – I met my girlfriend in 2004). Regarding Saber, when an infinitive follows it, it turns the meaning into “know how to ___.” Essentially, you don’t need to add “cómo” to the sentence to say “how.” For example:
Yo sé jugar al tenis muy bien. I know how to play tennis very well.
Nosotros sabemos hablar español. We know how to speak Spanish.
A common MISTAKE that I see frequently is the use of cómo between the two verbs (saber + infinitive), like this — Yo sé cómo jugar al tenis. This is INCORRECT.
Here is the rule:
Saber + infinitive = to know how to do something
But don’t get me wrong, you can attach “cómo” after Saber, but for a different purpose. For example:
¡No sé cómo tú comiste el plato todo! I don’t know how you ate the whole plate