This is an interesting question, particularly because of this dichotomy:
- This is a type of apple. (not apples)
- These are two types of apples. (not apple)
I think that the construction of the form "two types of apple" sounds more than stilted; it just plain sounds awkward, and I would be surprised that it sounds familiar and normal to anyone (at least speaking for US English).
The idea that a plural form would be used for a class is actually not strange at all in English. To express the fact that I like things belonging to the "apple" class, I would say:
I would not be able to use the singular to express this:
- *I like apple.
- *I like an apple.
- *I like the apple.
Saying "I like apples" doesn't even imply that I am talking about multiple apples; one could say this, for example:
- I like apples, although I've only ever had one in my life.
So, saying "I like all sorts of apples" seems to jibe perfectly with the rest of English grammar.
This means that the strange case is actually this one:
- This is a type of apple. (not apples)
Saying "this is a type of apples" is definitely not natural or familiar. It seems that, in phrases like "type(s) of X" ("kind(s) of X", etc.), there is generally number concord between the type-word and the class itself. Why that is, I don't know.
From The Cambridge History of the English Language: English in North America, p. 332,
by John Algeo, via Google Books:
When thou, thee, and thine
dropped out of the language in the
early Colonial period on both sides of
the Atlantic, speakers felt a need
nonetheless to distinguish between
singular and plural forms. The
earliest attempt was simply to make
verb agreement do the work: speakers
would say you was for the singular
and you were for the plural.
Beginning in the eighteenth century,
this sensible solution was met with
heavy resistance from purists, and
you was became heavily stigmatized by the end of the nineteenth century in
America (though it has by no means
dropped out of colloquial speech in
the United States).
Best Answer
In English it's usually an uncountable (mass) noun, with "piece of spaghetti" or "strand of spaghetti" used for the "singular", but in Italian spaghetti is plural (of "spaghetto"), and they freely use it as such. (See this website.) All the citations in the OED for "spaghetti" are consistent with its being used as a non-count noun, so I don't think Maugham's "his spaghetti were…" was ever normal usage.