Two actions in the past: one is longer and already going on, the other is short and cuts across it. English marks that difference with two past tenses, and it is one of the first places learners slip.
The pattern: Past Continuous + when + Past Simple
The longer, background action takes the Past Continuous: was cooking. The short event that interrupts it takes the Past Simple: came. The word when connects the two.
- She was cooking dinner when I came home.Background action in progress, then a short interruption.
- I was reading when the phone rang.Same pattern: an ongoing activity, then a sudden event.
- They were watching a film when the power went off.The power cut is the short event that breaks in.
In Ukrainian, «вона готувала» doesn’t show whether she finished. English does: was cooking means in progress, while cooked means the action was completed. Choose the form based on what you want to say.
You can switch the order: When I came home, she was cooking dinner. If the when-clause comes first, put a comma after it. If it comes second, no comma is needed.
when or while?
Both words can mean “at the time that”, but they pair with different tenses:
- when + Past Simple for a short, one-moment event: when I came home, when the phone rang.
- while + Past Continuous for a longer action: while she was cooking, while we were talking.
- While she was cooking dinner, I came home.Same meaning as the original, with while on the longer action.
- While we were washing the dishes, someone rang the doorbell.The long action uses while; the doorbell is the short event.
When two actions run at the same time, both can take the Past Continuous: While I was cooking, she was reading.
Common mistakes
- She cooked dinner when I came home is grammatical, but it suggests the dinner was already finished. For an action in progress, use was cooking.
- She was cooking dinner when I was coming home — the short event that happened should be in the Past Simple: came.
- She was cook dinner — after was or were you need the -ing form: cooking.
If the Past Continuous is still new to you, start with our post on the Past Continuous, and for regular and irregular past forms see Past Simple: regular and irregular verbs.
Check yourself
Try it first, then reveal the answer:
1.Put the verbs in the right tenses: I ___ (read) a book when the phone ___ (ring).
Answer
I was reading a book when the phone rang.
2.Rewrite with while: I came home when she was cooking dinner.
Answer
While she was cooking dinner, I came home.
3.Correct the mistake: She cooked dinner when I was coming home.
Answer
She was cooking dinner when I came home.
New mini-lessons come out on our YouTube channel. To use these tenses in real conversation, not just recognise them, book a free trial lesson.
