"Do you know where I can find a public telephone?"
Translation:Você sabe onde posso encontrar um telefone público?
After CAN, we use the verb in infinitive (ending in -ar, -er, -ir, -or). This is the why you say encontrar. If you dont use "can", then you say "encontro"
I had similar questions when I first started. To translate "I like to swim and walk" I would write "eu gosto de nado e caminho" because my thought was that I'm doing the swimming and walking so I should conjugate those as well in the first person. But it's wrong. Only the first verb is conjugated.
Yes. Like you dont say "she doesnt works", "they didnt traveled" and so, we just conjugate the first verb. So,after any modal we use infinitive, as well as "eu tenho que correr", "eu gosto de estudar",...