At a glance
～以来 means "since" or "ever since" a point in the past. It says that a state has continued from that point until now.
Verb て-form + 以来
Noun + 以来
日本に来て以来、ずっと日本語を勉強しています。 Ever since I came to Japan, I've been studying Japanese.
How to form it
以来 attaches to the て-form of a verb or directly to a noun.
| Attaches to | Dictionary form | + 以来 |
|---|---|---|
| う-verb | 会う | 会って以来 |
| る-verb | 始める | 始めて以来 |
| する | 結婚する | 結婚して以来 |
| 来る | 来る | 来て以来 |
| Noun | 卒業 | 卒業以来 |
| Noun | その日 | その日以来 |
The verb takes the て-form, not the た-form. A noun comes directly before 以来, with no の.