Auxiliary verbs

Types and rolls of auxiliary verbs

Auxiliary verbs work mainly as part of a predicate. Most of them express the feelings of the speaker. The ending in “da” is similar to Na-adjectives, and auxiliary verbs ending in “i” are similar to the conjugation of I-adjectives.

Conjecture / らしい, ようだ, みたいだ, そうだ

These auxiliary verbs indicate that the speaker is estimating based on information obtained from someone or something.

らしい, ようだ, みたいだ or そうだ usually transrated to “seem”, “like” or “look like”.

If you change だ to です, it will be a polite expression. ようです, みたいです, そうです

Examples

e.g. 彼かれは東京とうきょうに住すんでいるらしい。

He seems to live in Tokyo.

らしい represents an informed estimation.

e.g. 彼かれはりんごが好すきなようだ。

He seems to like apples.

e.g. 彼かれは学生がくせいみたいだ。

He looks like a student.

みたいだ sounds like spoken language.

e.g. 彼かれは元気げんきそうだ。

He looks fine.

そうだ is used when judging from the impression of appearance.

Hearsay / そうだ

This auxiliary verb is used to tell the listener what the speaker has heard from others.

If you change だ to です, it will be a polite expression. そうです

Example

e.g. 彼かれは引ひっ越こしたそうだ。

He seems to have moved.

The speaker heard that he had moved.

Non-conclusion / だろう, でしょう

These auxiliary verbs are used when expressing the speaker’s opinion.

だろう or でしょう are usually translated to ”I think”, “I guess” or “will”.

These auxiliary verbs have no conjugation form as an exception.

Examples

e.g. 彼かれは怒おこるだろう。

(I guess) He will get angry.

e.g. 夕方ゆうがたから雨あめが降ふるでしょう。

(I think) It will rain in the evening.

でしょう is more polite than だろう.

Confidence / はずだ, ちがいない

These auxiliary verbs are used when expressing the speaker’s strong opinion.

はずだ or ちがいない are usually translated to “should be”, “must be” or “be supposed”.

If you change だ to です, it will be a polite expression. はずです

Examples

e.g. 彼かれは喜よろこぶはずだ。

He should be pleased.

e.g. 彼がやったにちがいない。

He must have done it.

Explanation / のだ, わけだ

These auxiliary verbs are used when expressing the current situation or what was taken for granted.

わけだ is usually translated to “that’s why” or “for that reason”.

If you change だ to です, it will be a polite expression. のです(or んです), わけです

Examples

e.g. 彼かれは機嫌きげんが良いいのだ。

He is in a good mood.

e.g. 彼は財布さいふをなくしたの？それで元気げんきがないわけだ。

Did he lose his wallet? That’s why he’s not well.

Obligation / べきだ, なければならない, いけない

These auxiliary verbs are used when expressing obligations or advice.

べきだ is usually translated to “should”, なければならない is usually translated to “have to” or “must”.
いけない is usually translated to “must not”.

If you change だ to です, it will be a polite expression. べきです

Examples

e.g. 彼かれは走はしるべきだ。

He should run.

e.g. 彼は走らなければならない。

He has to run.

e.g. 彼は走ってはいけない。

He must not run.

Practice

Translate the following sentences into English, paying attention to the auxiliary verbs.