Because unfortunately that's how you learn them. Duolingo doesn't have some vocab list you have to memorize before a lesson, and you won't get idiomatic expressions the first time either. It stinks, but this system seems to work wonders better than the memorization list method taught in schools.
Seems DL will accept "That was part of the job" AND "He did part of the work". Can an Italian speaker confirm that those are both correct? I put " He was doing part of the work", which seems very similar to DL's second option. In fact, as Italian does not really have a Simple Past, they seem identical.
Duo what is wrong with you? ( lei faceva, lui faceva, quello faceva parte del lavoro)
Can anyone tell me whether "he made part of the work" would be possible? I was thinking of an art installation made by several artists (my son does this sort of thing, so it was on my mind). Could "lavoro" be used for this kind of "work" or would you have to use another word?