I found that my instinct was to say 'All I can see is the cat's whiskers' but my instinct was also to say 'All I can see are the cat's eyes'.
After some thought, either this is just a personal quirk of my own experience of the English language, or this is something that is idiomatic (perhaps only in my native British English or even more locally, my Scottish background) or . . . .
. . . . it is a genuine conceptual effect of expressing a clearly definable number (a pair) as a plural and expressing an indefinable excess as a collective singular.
Does the indefinability of a number (greater than, say a pair or a trio) affect it's usage as a collective singular in situations where there is an ambiguity of grammatical expression ?
