Somewhere, something, somebody & someone referring to multiple things

Solution 1:

You have not fully understood what the dictionary is saying.

“I saw you somewhere in France.”

Somewhere is a singular noun and an adverb:

“I saw you somewhere (adv.) in France.” = at an unknown/unspecified place.

“The ship has come from somewhere (n.) and is going to somewhere(n.) = an unknown/unspecified place.

The plural of “somewhere(n.)” is “some places”. - two words   “The ship has come from some places in Africa.”

“The battles were fought at some places in France.”

Something is a singular noun:

“Something(n.) is making a noise.” / “I need something(n.) to write with.” = an unknown/unspecified thing /object.

The plural of “something (n.) is “some things” – two words

“I will put some things into the attic.”

Somebody and someone are nouns:

“Somebody(n.) / Someone(n.) is making a noise.” / “I need somebody(n.)/ someone(n.) to help me.” = an unknown/unspecified person.

The plural of “somebody (n.) / someone(n.) is “some people” – two words

“Some people are making a noise.” / “I need some people to help me.”