Page 190 - Basic Japanese

The relationship between the plain forms of the verb (iku
and itta) and the word koto is that of modifier to modified,
with the meaning ‘which (does or is).’ That is, a koto WHICH

iku or itta, a koto ABOUT WHICH YOU CAN SAY iku or itta. The

plain inflected forms in Japanese can modify a noun (like
koto) directly, without any particle. Nouns, on the other

hand, have to be followed by the particle no (or a modifying
form of the copula na or no, see 5.3) to modify another noun.

The modifier relationship is further discussed in 5.1. More
examples of expressions with koto:

“Sono hon o yonda koto ga arimasu ka.

“Have you (ever) read that book?”

“Īe, arimasen.”
“No, I haven’t.”

Shikago ni wa itta koto ga arimasen. Kyonen made wa

Nyū Yōku ni mo itta koto ga arimasen deshita.
I haven’t been to Chicago yet. Until last year I
had never even been to New York.

“Ano hito no koe ga iya da to omou koto wa arimasen

ka.”
“Don’t you sometimes (ever) dislike his voice?”

“Tokidoki arimasu ne.”