て以来【ていらい】

The grammar pattern て以来 (ていらい) means "since" or "ever since" and is used to express that a certain state or situation has continued from a specific point in the past up to the present. It emphasizes that the change or event marked by the て-form was a turning point, and the resulting situation has persisted ever since.

Formation

Attach いらい以来 to the て-form of a verb:

Key nuances

• て以来 implies that the situation described in the second clause has been continuously true from the time of the event in the first clause. It is not used for one-time events that happened after another event – for that, use てから instead.

• The second clause typically describes a lasting state or habitual action, often with words like ずっと、いちど一度も、or まいにち毎日.

• て以来 carries a somewhat formal or literary tone compared to the more casual てから. It is common in written language and formal speech.

て以来 vs. てから

Both mean "since" or "after," but they differ in nuance:

• てから simply indicates sequence ("after doing X, Y happened") and can be used for both one-time and ongoing situations.
• て以来 specifically emphasizes that a state has continued without change since the event. It cannot be used for short, one-time follow-up actions.

✕ 朝ご飯を食べて以来、学校に行った。(Unnatural – going to school is a one-time action) ○

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