Page 165 - Basic Japanese

* The w at the end of a consonant verb is pronounced and heard only if it is
followed by the vowel a.

The endings, then, are as follows:

Imperfect: -ru after a vowel stem, -u after a
consonant stem

Infinitive: (-ZERO) after a vowel stem, -i after a

consonant stem

Perfect: -da after -g, -b, -m, and -n stems; -ta
after all other stems

Gerund: -de after -g, -b, -m, and -n stems; -te

after all other stems