Two rules on hyphens:
1. Use a hyphen to separate two (nearly) identical parts of a word. Examples: dahan-dahan, turo-turo, luko-luko, taba-taba.
2. Use a hyphen between a prefix and a root word
when the root begins with a vowel.
Do not use a hyphen if the root begins with a consonant.
How do you know something is a prefix?
Some frequently-used prefixes: