"I got up."

Translation: Codais i.

[Ash473779]

Is 'dw I wedi codi' not a valid answer?

[mizinamo]

That's "I have got up" -- different tense from "I got up". (Also, i is lowercase in Welsh.)

If you want to use a helping verb to save remembering the simple past and simple future endings, use gwneud: Mi wnes i godi / Wnes i godi / Gwnes i godi.