Page 344 - Basic Japanese

in these forms:

These plain tentative verbs are used when you want to

embed a sentence that would, if not embedded, end in the
polite tentative with the meaning ‘let’s do so-and-so’ or ‘I

think I’ll do so-and-so.’ For example, if a friend says to you
Kōen e sanpo ni ikimashō ‘Let’s go to the park for a walk,’ you

could report his suggestion this way: Taro wa koen e sanpo ni ikō
to iimashita ‘Taro suggested we go to the park for walk.’ If you

are thinking Go-han o tabete kara sugu benkyō shimashō ‘I’ll study

right after eating,’ you will probably say Go-han o tabete kara
sugu benkyō shiyō to omoimasu ‘I’ll think I’ll study right after

eating.’ Of course, if you’re really talking to yourself, you
won’t use polite forms at all; you’ll use plain style instead.

Here are some further examples of the plain tentative:

５時半ごろに家へ帰ろうと思っていましたが，帰れま
せんでした。

Go-ji han goro ni uchi e kaerō to omotte imashita ga,
kaeremasen deshita.