Si quieres, quedamos en la cafetería después de clase.

Because Spanish normally uses the present indicative after si when talking about a real or possible condition in the present or future.

• Si quieres... = If you want...
• Not Si quieras... in this kind of sentence

The subjunctive does not usually follow si in ordinary if clauses like this one.

Here quedamos comes from quedar and means something like:

• we meet
• we arrange to meet
• shall we meet?

In Spain, quedar is very commonly used for making plans to meet someone.

So quedamos en la cafetería is not literally about “remaining” somewhere. It is about agreeing on a meeting place.

Because quedar and quedarse mean different things.

• quedar = to arrange to meet / to be left / to suit / to end up, depending on context
• quedarse = to stay / to remain

So:

• Quedamos en la cafetería = We meet at the cafeteria
• Nos quedamos en la cafetería = We stay in the cafeteria

That little nos changes the meaning a lot.

Yes, it is present tense, but Spanish often uses the present to talk about a planned future action.

So quedamos here is present in form, but future in meaning:

• Shall we meet / We can meet

This is very natural in Spanish, especially for arrangements and suggestions.

Spanish often leaves subject pronouns out because the verb ending already shows who the subject is.

• quieres clearly means you want
• quedamos clearly means we meet / we arrange

So:

• Si quieres, quedamos... is completely natural
• Si tú quieres, nosotros quedamos... would usually sound unnecessary unless you want extra emphasis or contrast

Because en is used for the place where the meeting happens.

• quedamos en la cafetería = we meet at/in the cafeteria

If you used a, it would suggest movement to the cafeteria rather than the location of the meeting itself.

Compare:

• Vamos a la cafetería = We go to the cafeteria
• Quedamos en la cafetería = We meet at the cafeteria

In Spanish, when talking about routine activities or institutional settings, the article is often omitted.

So:

• después de clase = after class in a general, natural sense

If you say después de la clase, it sounds more like you mean one specific class session, with more emphasis on that particular class.

Both can be possible, but después de clase is the most natural general phrasing here.

Si quieres softens the suggestion. It makes the sentence sound more polite, less direct, and more casual.

It is similar to:

• If you want
• If you’d like
• If you want, we can meet...

Without it, Quedamos en la cafetería después de clase is still fine, but it sounds a bit more direct.

It is standard and very natural to write a comma after an opening clause like Si quieres.

So:

• Si quieres, quedamos en la cafetería...

That comma marks a pause and makes the sentence easier to read.

In very informal writing, people sometimes leave commas out, but with normal punctuation, the comma is a good idea here.

Yes. Spanish word order is fairly flexible.

For example, these are all possible:

• Si quieres, quedamos en la cafetería después de clase.
• Si quieres, quedamos después de clase en la cafetería.
• Quedamos en la cafetería después de clase, si quieres.

The basic meaning stays the same, but the emphasis changes slightly.

• en la cafetería earlier = the place is highlighted a bit more
• después de clase earlier = the time is highlighted a bit more

Not always.

In Spain, cafetería often means a café, snack bar, or casual place to have coffee and food. In a school or university context, it can also refer to the campus cafeteria area.

So the exact image may depend on context. It does not always mean a large self-service dining hall in the English sense.

Yes, quedar for meeting up is especially common in Spain.

A speaker from Spain very naturally says things like:

• Quedamos mañana
• Hemos quedado a las seis
• ¿Quedamos después de clase?

In other Spanish-speaking regions, this may still be understood, but other expressions such as nos vemos or nos encontramos may be more common depending on the country.