Pasó vs Pasaste

[southUS]

When asking "How was your weekend?", should I use pasó or pasaste?

I've read that one is more formal than the other. I don't want to be rude to the person I'm speaking to.

Thank you,

[Rusty]

If the person you're speaking with is your friend, you would use familiar address (second-person conjugations).

Now, regarding your question about using the verb pasar, you need to use a certain structure. Something happens to someone. 'Happens', or 'happened', in this case, is the literal translation you should think of when using this structure. The structure takes an indirect object. That depicts the 'to someone' in the transliteration. The 'something' is the subject. In your case, it's 'the weekend'.
The model is taught in the infinitive form, so you must choose the right pronoun and properly conjugate the verb. Here is the model: pasarle el fin de semana

The model contains the indirect object pronoun ('le') suffixed to the infinitive.
When conjugating into any mood but the imperative, the pronoun is removed from the infinitive and placed prior to the verb. If the 'to someone' is properly addressed or referenced using a third-person singular pronoun, nothing more needs to be done (since 'le' is the third-person, singular form). Otherwise, you'll need to choose the correct indirect object pronoun to use. If you're talking to only one person, a singular form is used. If not, a plural form is substituted. If you're talking to a friend, the second-person form should be used ('te' instead of 'le').

So, assuming the person being addressed is your friend, 'pasarle el fin de semana' becomes 'te pasa el fin de semana' in the present tense, the verb agreeing with the subject - 'el fin de semana'. The preterite tense would make it 'te pasó el fin de semana'. So, the entire phrase is: ¿Cómo te pasó el fin de semana?

Another way to say the same thing is to use irle el fin de semana, like so:
¿Cómo te fue el fin de semana?

Did my long-winded explanation make sense?

[southUS]

It made perfect sense. My first inclination was to use "cómo pasaste el fin de semana".

[Rusty]

You're addressing a friend, then, and your question means "How did you spend the weekend?" It's OK to use either question. You'll get a more detailed report with one of the two.

[southUS]

Muchas Gracias. I appreciate your help.