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Is it supposed to be two words or one word only?
Sometimes I see nouns consisted of two words and I wonder why that is (I can't recall which ones though)
Comments  
Both are correct.
diAAnaPIs it supposed to be two words or one word only?
The accepted orthography is two words, although it may be close to being accepted as a compound.
http://www.oxforddictionaries.com/us/definition/american_english/time-frame
diAAnaPSometimes I see nouns consisting of two words and I wonder why that is
It is a natural evolutionary process in language for the formation of compound words.
They begin as separate words and may gradually fuse, becoming one compound word.
Students: We have free audio pronunciation exercises.
AlpheccaStars diAAnaPIs it supposed to be two words or one word only?The accepted orthography is two words, although it may be close to being accepted as a compound. http://www.oxforddictionaries.com/us/definition/american_english/time-frame diAAnaPSometimes I see nouns consisting of two words and I wonder why that isIt is a natural evolutionary process in language for the formation of compound words. They begin as separate words and may gradually fuse, becoming one compound word.
Then what about "life span" and "life time"?
I hardy see these two nouns written in a single-word form
diAAnaPSometimes I see nouns that consist of two words and I wonder why that is
Join the club. The only way to be sure is to look them up in a dictionary. That's what I do.

CJ
CalifJim diAAnaPSometimes I see nouns that consist of two words and I wonder why that isJoin the club. The only way to be sure is to look them up in a dictionary. That's what I do.CJ
LOL
Why in the world is your correction over "consisted of" different from that suggested by another member?
Just curious:)

And BTW,
some words are rather new and are made up or highly technical, in which case, they won't be covered by those dictionaries,
unless there's a dictionary that covers this particular kind of jargon that I don't know about?
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diAAnaPWhy in the world is your correction over "consisted of" different from that suggested by another member?
Because there are two possible forms:

1) Sometimes I see nouns consisting of two words. (non-finite relative clause)
2) Sometimes I see nouns that consist of two words. (relative clause)
diAAnaPsome words are rather new and are made up or highly technical, in which case, they won't be covered by those dictionaries,unless there's a dictionary that covers this particular kind of jargon that I don't know about?
You can find technical (medical, legal, computing) dictionaries on line.
For example, overclock is a computer term. Although it is relatively new, it is still in eight different dictionaries:
http://www.onelook.com/?w=overclock&ls=a

New words are added all the time to dictionaries. In June 2015, one addition (out of 500) to the OED was the compound word crowdfund.
http://public.oed.com/the-oed-today/recent-updates-to-the-oed /

Note: The online version currently has the gerund: crowdfunding, but not the verb.
Once the OED accepts a new word, it is likely to appear as a new entry in other dictionaries.