re-
Hyphenate words beginning with re- only where re means again and only if the hyphen is necessary to make a distinction or to aid readability or pronunciation; otherwise do not hyphenate.
Examples:
- re-form to distinguish from reform
- re-cover to distinguish from recover
- re-enter for better readability than reenter
- regroup
- reiterate
- retest
re-evaluate
Hyphenated.
reinforce, re-enforce
You can reinforce your effort. You can reinforce your work colleagues. You can also reinforce concrete. You can’t re-enforce any of them. Reinforce means strengthen. It can be used in the physical sense and in the sense of encouraging or supporting people. It’s sometimes incorrectly written as re-enforce, which would mean “compel observance again”.
rein in
When you limit or control something you can be said to rein it in. Take care with the spelling. Sometimes people write “reign in” but that’s incorrect. You can’t reign unless you’re a monarch.
restart
No hyphen.
restaurateur
Not restauranteur.
résumé
Another word for CV. Write it with both the accents.
reuse
No hyphen.
rite of passage
Not right of passage.
roadmap
One word.