There are a number of words in English that are written with or without a hyphen or with or without a space, for example check in vs. check-in, and the space and hyphen makes a difference in meaning!  Usually the difference is a change in the part of speech of the word, such as noun verses an adjective.

So, wouldn’t it be helpful to see a list of these words and their different parts of speech. Yes, yes it would!  That is exactly what you have here. Below I have put together a group of words that are both hyphen or unhyphenated or compound or not compounded.  I’ve also listed their parts of speech and on some I’ve given an example of use.

If you have any questions about this please post your question in the comment area below.

backyard (noun) vs. back-yard (adjective)

build up (verb) vs. buildup (noun)

check in (verb) vs. check-in (noun)
Example: You need to check in at the check-in desk before you can enter.

check out (verb) vs. checkout (noun)

clean up (verb) vs. cleanup (noun)

close out (verb) vs. closeout (noun)

cook out (verb) vs. cookout (noun)
Example: Having cooked out last night, I’m not sure I want to go to a cookout today.

cut off (verb) vs. cutoff (noun & adjective)

first-year (adjective) vs. first year (noun)
Example: During the first year of college all the first-year students have a chance to try out new classes before registering.

hometown (noun) vs. home-town (adjective)

line up (verb) vs. lineup (noun)

log in (verb) vs. login (noun)

long term (noun) vs. long-term (adjective)

make up (verb) vs. makeup (noun)
Example: Jane always tries to make up new ways to apply her makeup so that it looks fun and different.

set up (verb) vs. setup (noun and adjective)

short term (noun) vs. short-term (adjective)

start up (verb) vs. start-up (noun)
Example: It is time to start up the meeting for all the new Silicon Valley start-ups.