I'm curious, why is "på" required? Would "litar" translate into something else without it?
It's one of those annoying particle verbs - it always takes a på. It doesn't translate into anything else if you remove it - it just becomes nonsense.
As I assumed then. Thank you for the response!
It could help if you think of "litar på" as "to put one's trust on..."
Would "Jag tro min son" be acceptable?
No, that means that you believe in him. And you have to use the present tense tror in the sentence.
I tried jag tror min son .. It's wrong :/
Yes, it means you believe in him.
why jag sättar min son was not correct?
There's no verb sättar. There is a verb sätter, but that means 'puts'.
If it were turned into a question, would it be " Litar jag på min son? "