I'd like to know the meaning of the following sentence.
#1) He hasn't done his homework yet.
Can I use #1) when he has started his homework and hasn't finished ?
Or does #1) mean he hasn't started his homework?
1) He hasn't done his homework yet.
=> He hasn't started it.
Compare: He didn't do it.
Note, some speakers might use "hasn't done" to mean hasn't completed,
EX: He hasn't done/completed his homework yet.