So, how is the plural used? If I have five oranges, do I have vyakula? Would I, if I had some oranges, some rice, and some sausages? I think in English I would only use the plural, if I were talking about cuisines, such as the foods of the various peoples of Asia, or some such.
I would use chakula to describe the food that makes up a meal. So, if a family is sharing several dishes, I would refer to that as chakula. But if a group of students has each brought their own lunch, I would refer to those collectively as vyakula.
OK, so essentially you would use the plural for different kinds of food, right? In my first example above, if I just had 5 oranges (but did not want to specify what kind of food it was) I might call it chakula, but if I had a bag of oranges, mangoes, and onions, I might want to call it vyakula?
I have never heard it used as "foods". I think vyakula would only be "meals".
You can check out the tips section. More than one item becomes vyakula. If you have five oranges you have "machungwa tano". Baadhi means some; so you can have baadhi ya machungwa, baadhi ya wali and baadhi ya sausage.
If you have five oranges, you would have "machungwa matano" numbers have to agree with the noun class for 1, 2, 3, 4, 5 and 8.
"some" in the sense of "part of" - for baadhi; as far as I know that would only be used as part of something bigger (not some as in a few)