>>14
"two monkeys"?? ＷＨＡＴ！？ ＮＯＮ！！
There is already "two", so it is a self-evident truth that
"monkey" is plural. It's redundant!!
You should say "two monkey"!!

>>15
Wait!! The example is too simple and doesn't reach the problem.
"Goats" can be said in other words "Some Goats" or "Many Goats" etc.
And if "my newspaper was eat" is a most important meaning,
it is not important that "goat" is plural or not.
A problem is practical usage of the plural form.
If you want to say "plural sheep", you don't say "sheeps", do you?