(て-Form VERB/VERBAL NOUN/NOUN) + 以来 as “since (V/VN/N)”
The word 以来 (いらい) translates to “since, henceforth, etc.’ and can be used directly after the て-Form of a verb, a verbal noun (without the inclusion of する), or a noun to express “since ____,” in which the blank is filled by the word used. When this grammar pattern is employed with a noun, the noun must represent a certain event, activity or time; and when used at all, whether with a verb, verbal noun, or noun, the word must represent something that occurred in the past. As is with the English language, in the Japanese language it does not make grammatical sense to say, “since ____” when what fills in the blank does not represent something that has already occurred.
Hitorigurashi irai, iroiro na koto o manabimashita.
(I’ve learned many things since living alone.)
(Kare wa 21 sai ni natte irai, mainichi no you ni osake o nomimasu.
(Ever since he turned 21, he has been drinking alcohol almost every day.)
Sotsugyou irai, kanojo ni ichido mo atte inai.
(Ever since graduation, I haven’t seen her even once.)
Atarashii computer o katte irai, game o shite bakari imasu.
(I’ve been doing nothing but playing games since I bought a new computer.)