一

also 一つ · １つ

1. numeral one
2. noun, often used in itemized lists for one thing
3. after a noun only
4. with a verb in negative form (not) even
5. noun, adverb just (e.g. "just try it")
6. takes の some kind of; one type of

いち also １ · 壱 · 弌

1. numeral, prefix, 壱, 弌 and 壹 are used in legal documents one; 1
2. takes の, suffix best
3. takes の first; foremost
4. noun beginning; start
5. prefix, before a noun a (single); one (of many)
6. noun, card games ace
7. bottom string (on a shamisen, etc.)

ひと · ひ · ひい

1. prefix, esp. ひと one
2. numeral, when counting aloud, usu. ひ or ひい one

イー

1. numeral one

いっち also 逸

1. adverb most; best

いつ

1. numeral one
2. noun same (mind, path, etc.)