At a glance
～ところを means "at a time when (someone is busy, resting, etc.)". It is used in formal apologies, thanks and requests. It is also used for catching or interrupting someone in the middle of something.
Verb (plain) / い-adj / Noun + の ＋ ところ(を) ＋ main clause
お忙しいところをすみません。 I'm sorry to bother you when you're busy.
How to form it
| Attaches to | Example | Register |
|---|---|---|
| Verb (plain form, often ている) | 寝ているところを | Neutral, also casual |
| い-adjective | お忙しいところを | Formal |
| Noun + の | お休みのところを | Formal |
な-adjectives take な before ところを, but this is less common.
を is optional. It is often dropped in the formal set phrases (お忙しいところすみません). It is usually kept in the "caught in the act" use.