占ううらなう

How 占う conjugates · godan う-verb

Only the last kana changes: う becomes わ, い, え or お.

Which one depends on the ending. The five are one line of the hiragana chart — same consonant, vowels あ・い・う・え・お — and everything before that kana never changes.

The て and た forms are the only two that don't follow this pattern. Every う-, つ- and る-verb has the same って there.