Use kan du, kunne du and jeg vil gjerne in everyday situations, with specific, understandable requests.
Make the request clear first
Begin with the action you need: explain, repeat or send. Do not bury the request in a long introduction. Kan du is useful in many everyday contexts; tone and the relationship also matter.
Kan du hjelpe meg med denne oppgaven?
Can you help me with this exercise?
Kunne du for a softer request
Kunne du can soften a request, although kunne has past-related uses elsewhere. Here it functions as a polite request rather than a literal question about the past.
Kunne du gjenta det litt saktere?
Could you repeat that a little more slowly?
Gjerne when stating a preference
Jeg vil gjerne helps when arranging an appointment or requesting information. Add a brief reason when useful. Vær så snill may suit some requests, but politeness does not require it in every message.
Jeg vil gjerne få mer informasjon om kurset.
I would like more information about the course.
Try it yourself
Turn a direct instruction into a polite request and specify whether you need a repeated sentence, a word explanation or a new appointment.