"Sommige appels zijn zuur."
Translation:Some apples are sour.
"Sommige" means some, but not all. It points to a subset of a larger group (in this case, all apples).
"Wat" can mean some, a few, a couple of, a bit of. It is simply an undetermined, small amount.
- Sommige honden drinken wat water - Some (not all) dogs drink some (a bit of) water.
Does it more closely mean: Some of the apples are sour (even though they are all in the same batch of apples)? Or: Some (varieties of) apples are sour (as opposed to other varieties)?
Not really. I have challenges too but keep at it and keep revising/practicing before adding something new to your vocabulary until you KNOW that you are capable of handling More. Strengthen what you have so you don't have to worry about them again,except on VERY FEW occasions then move on. It will work just keep at it. YOU'RE SURE GOING TO GET THERE! Only be a little patient with yourself and dont expect too much for yourself, so you dont drive yourself too hard you shut down. Okay? Hope you feel encouraged