So what's the difference between jätte- , väldigt and mycket? I thought mycket meant "much"
No difference in meaning, but jätte- is more colloquial than the others (and väldigt is slightly more colloquial than mycket).
Would it be generally correct to assume: jätte-=really väldigt=very mycket=much ?
The Swedish noun en jätte (a giant) may indicate how to interpret the prefix jätte-.
Almost, except I would just lump "mycket" into "very" as well. You can't really say "I'm much tired", and even if you can I'm pretty sure it's far more uncommon than "mycket" is in Swedish.
is the "base form" väldig without the t? why is there a t? does "väldigt" matches with another word bc of the t at the end? or is "väldigt" a whole word, that doesn't changes?
I think that usually when there is a "t" in the end of an adjective it turns it to an adverb. In other cases it means that the following word (object or subject) is an "ett" word. if its an "en" word the adjective stays the way it is. Am I right?
It's an adverb that modifies the adjective, not an adjective that modifies the subject. The normal adverb form is -t.
The tips and tricks in the browser version lists the endings as -t, -tvis, and -en.
I don't really think they're synonymous. To me, "very" implies a far higher tiredness level than "pretty". The former is "I need to go bed now", the latter is "I can keep going for a bit longer".
Is trötta used for the "exhausted" meaning of tired rather than "sleepy" tired? If so, what is sleepy?
I put "We are very sleepy" and it wasn't accepted so I was wondering whether trötta isn't as flexible as the word tired is in English.
It can refer to both just like the Swedish "tired", but if you want to specify "sleepy" you can use the word "sömnig".