My teacher said "Who and what as the subject always take a singular verb". Is that true?
***** NOT A TEACHER *****
Hello,
Perhaps your teacher was thinking of these rules:
1. When "who" and "what" are used to ask for the subject, they most often have singular verbs:
a. Who
is working tomorrow? Phil, Lucy and Shareena (are working tomorrow).
b. What
lives in those holes? Rabbits (do).
2. When "who" and "what" ask for the complement, they can have plural verbs:
a. Who
are your closest friends? (My closest friends are) Naomi and Bridget.
3. Relative
what-clauses are normally the subject of a singular verb:
a. What she needs
is friends. (More natural than
What she needs are friends.)
[Personal note: Maybe some native speakers feel that "What she needs are friends" is
more natural than "What she needs is friends."]
Complete credit for those rules go to Mr. Michael Swan in his
Practical English Usage (1995 edition, entry #509.3 on page 533).
4. Here are a few more examples from a very strict teacher named Wilson Follett in his
Modern American Usage (1980 edition, page 233):
a. What to watch for _____ such things as dry, sandy layers or hardpan.
b. What they saw _____ the white sand cliffs on the eastern coast.
c. What these gentlemen need _____ new moral values.
Mr. Follett says that correct English requires the singular verb: is, was, is. [Personal note: in 2012, maybe many native speakers would have no problem with: are, were, are. Mr. Follett does admit that a "correct" sentence such as "The only thing untouched
was the tent
s" is "awkward."]
James