Conjugation of Verbs and Adjectives in Romanized Japanese

by Paul Burchard

To use the tables, first determine the class and radical of the word in question. If the dictionary form of a verb ends in -eru or -iru, it is a class-I verb (see Note 0 for exceptions), and its radical is obtained by removing the -iru. The irregular verbs kuru and suru are handled specially, along with the various forms of the contraction desu (class D in the chart) and its plain form da. Any other verb is a class-II verb, and its radical is obtained by removing the -u (see Note 1). A true adjective (class A in the chart) ends in -ai, -ii, -oi, or -ui, and its radical is obtainedby removing the -i.

Starting with the radical, intermediate endings (zero or more) may be added, after which exactly one terminal ending must be added. As the endings are added on, the appropriate sound changes and other adjustments should be made, as described in the Notes. Also, each intermediate ending will change the class of the compound as indicated in the chart. In Japanese writing, the ending as written in hiragana includes the final roman letter of the radical (except for class-II verbs whose radical ends in a vowel). This letter will of course be modified by sound changes when appropriate.

Not all combinations and orderings of the endings described here are acceptable. For example, when an explicit combination such as Passive Causative is given, then the individual Passive and Causative endings should not be combined. The order of intermediate endings is given roughly in the order in which they should be combined, when such combinations are acceptable.

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