Page 343 - Basic Japanese

I think he’ll probably go.

行っただろうと思います。

Itta darō to omoimasu.

I think he must have gone.

The word preceding darō may be a verb form, as above,
or it may be a noun or an adjective. For instance, to embed

the sentence Kyōshi deshō ‘He must be a teacher,’ you say
something like Kyōshi darō to omoimasu ‘I think he must be a

teacher.’ To embed the sentence kodomo wa nemui deshō ‘The

child is probably sleepy,’ you say something like Kodomo wa
nemui darō to omoimasu ‘I think the child is sleepy.’ And to

embed the sentence Kodomo wa nemukatta deshō ‘The child

must have been sleepy,’ you say something like Kodomo wa
nemukatta darō to omoimasu ‘I think the child must have been

sleepy.’ In rapid speech the form -katta darō is usually

contracted to -kattarō, so you will hear Kodomo wa nemukattarō
to omoimasu.

Just as there is a form darō corresponding to deshō, there
is a plain tentative form corresponding to the polite

tentative form of each verb. The polite tentative forms, you

will recall, end in -mashō. The plain tentative forms end in -yō
for vowel verbs, and in -ō for consonant verbs. The plain
tentative forms for kuru and suru are irregularly koyō and

shiyō. The plain tentative forms for verbs are also called

VOLITIONAL FORMS because they mean ‘let’s do…’ or
‘wants and intends to do….’ Here are some example verbs