Translation:I read a newspaper while he cooks.
Can I say: "Jag laser en tidning medan han lagar"? Because in many cases when we say "cooking", we mean "cooking some food".
No. The verb lagar in Swedish means mending or fixing and you need to specify what it applies to.
"Jag läser en tidning medan hon lagar bilen." - "I read a newspaper while she repairs the car"
"Jag läser en tidning medan han lagar hålet i skjortan" - "I read a newspaper while he mends the hole in the shirt"
I think of "lagar mat" as "fix food" (or even "make food", which is pretty colloquial (American) English. So I might translate this sentence as "I read the newspaper while he fixes food." (maybe more usual: while he fixes dinner"). Using "cooks" for "lagar mat" makes me ask, is there a difference in Swedish between "to cook" used transitively, and used intransitively? Is th construction different between "he is cooking" and "the porridge is cooking"?
'make food' is usually an accepted translation for laga mat throughout the course, but 'fix food' has an exact translation in fixa mat which is used pretty widely. (even more widely if you use the colloquial word käk for 'food', too). You should try to think of laga mat as 'cook'. :)
The porridge is not 'cooking' in Swedish. If things boil, they kokar, so you can say medan gröten kokar 'while the porridge is cooking' [i.e. boiling], but for food that isn't exactly "boiling" we can either use the passive lagas or tillagas, or some more specific expression. E.g. steken är i ugnen 'the roast is in the oven'.
Can anyone explain the difference between medan and medans? I used medan in a sentence when speaking to my swedish friend and he told me I should say medans instead. Thanks in advance!