I should know these verb rules by now but I still get confused sometimes. In this case I wrote "Vill du spelar med mig" instead of spela. I chose spela because I thought that I would use spelar if I were the actor, as in "Jag spelar med mina vänner." So is it the fact that I am asking a question that turns it into "spela?" Sorry for being dense.
Don't apologise - it's a great question.
- spela is the infinitive form
- spelar is the present tense
The reason that you need the infinitive here is that another verb - vill - is the main (modal) verb of the phrase, so the other changes into the infinitive.
English actually does this too, but it's a lot less obvious since it's restricted to the third person singular. Compare:
- Hon spelar fotboll = "She plays soccer" - plays is the main verb, present tense is used
- Hon vill spela fotboll = "She wants to play soccer" - wants is the main verb, infinitive is used
- Spelar hon fotboll? = "Does she play soccer?" - does is the main verb, infinitive is used
- Vill hon spela fotboll? = "Does she want to play soccer?" - does is the main verb, infinitive is used
As you can see, constructions vary a little between languages, mainly because of English using variations of "do" to form questions. But the basic principle is the same. :)
In English, a child might say this to another child, But an adult would definitely would not say that to another, unless, as AngelUare comented it was flirtatious. The English would simply say “do you want to play.? Vill du spela? Or Do you want to play (something) with me, like football or cards