Sometimes. E.g. The herd of sheep was difficult to round up. However: if referring to many sheep without using the word "herd" you would say The sheep were difficult to round up. So, if referring...
the kite flies above the clous.-PHS
Sometimes yes, sometimes no. It depends on the number (singular or plural) of the subject. Examples: There goes the bus. There go the buses.
words like physics, mathematics, forensics, statistics
The uncountable noun, clothing, takes a singular verb. Example: Clothing is optional.