Hmm. It's not strictly grammatical to us a singular verb with a plural object, but we do say "favorite food is cookies" or "fruit is pears" in casual speech. 1 and 3 are more proper, as is 4-1. 4-2 and 4-3 are not proper at all. The correct verb would be "are", not "is."
5 and 6 are both proper, but 5 would be more commonly used.
1. My favorite food is a cookie.
2. My favorite food is cookies.
3. My favorite fruit is a pear.
4. My favorite fruit is pears.
4-1 My favorite fruits are pears.
4-2. My favorite fruits is a pear. (?)
4-3. My favorite fruits is pears. (?)
(Are they all grammatical?)
5. My hobby is collecting coins.
6. My hobby is to collect coins.
(Are both grammatical? Which one is commonly used?)
2 answers
Hmm. It's not strictly grammatical to us a singular verb with a plural object, but we do say "favorite food is cookies" or "fruit is pears" in casual speech. 1 and 3 are more proper, as is 4-1. 4-2 and 4-3 are not proper at all. The correct verb would be "are", not "is.