Page 176 - Basic Japanese

(de ari), where the copula is always a phrase.

Verb and adjective infinitives are used before various
particles just as nouns are.

Kaban o tori ni ikimashita.

I went to pick up the suitcase.

Osoku made benkyō

shimashita.

I studied till late.

For emphatic contrast, a verb infinitive is sometimes
followed by the particle wa and some form of the verb suru:

Oyogi wa shimasen deshita ga, asobi wa yoku
shimashita.
I DIDN’T do any swimming, but I DID do a lot of
playing.

Similarly, an adjective infinitive is followed by wa and a
form of the verb aru:

Chīsaku wa arimashita keredomo, waruku wa arimasen
deshita.
It WAS small, but it WASN’T bad.