serious questions
 

why do we say killer whale and not killing whale
?forty million people has
why has not have

killing is a gerund (noun
people here means اناس
has describes million

مشكوووووووووووووووووووووور

killing is a gerund but killer is a noun
people is an adjective not a subject

if we say killing whale it means the act of killing the whale but when we want to describe a kind of whales we say killer.which is an adjective.