Form Use When / Until / While Word Order Signal words Exercises

Form

Positive

SubjectStructureExample
I / He / She / Itwas + verb-ingI was sleeping at midnight.
You / We / Theywere + verb-ingThey were talking in the corridor.

Negative

SubjectStructureExample
I / He / She / Itwasn't + verb-ingShe wasn't listening.
You / We / Theyweren't + verb-ingWe weren't watching TV.

Questions

TypeStructureExample
Yes/NoWas/Were + subject + verb-ing?Were you working at 9 p.m.?
Wh-Wh- + was/were + subject + verb-ing?What were you doing?

Use

UseExamples
Action in progress at a specific past timeCan include a second, shorter action mentioned at the same moment — but that second action does NOT interrupt or stop the action in progress. It just marks when it was happening.
At 10 p.m. last night, I was reading in bed.
This time yesterday she was flying to New York.
I was cooking dinner when she walked in. (she walking in doesn't stop the cooking)
Action in progress in the past interrupted by a short actionUsed with "until" + Past Simple. Unlike the use above, here the second action DOES interrupt and stop the action in progress.
I was playing a game until the electricity went out.
She was studying until her friends arrived.
Background scene in a story
The sun was shining and birds were singing when he left the house.
Two actions happening simultaneously
She was cooking while he was setting the table.

When, Until and While

These three words often go with the Past Continuous, but they don't mean the same thing:

Long action (Past Continuous) Short action (Past Simple)
I was walking home when it started to rain.
While she was studying, her phone rang.
When vs. Until vs. While: These three words all go with the Past Continuous, but they signal different things.

When marks the moment the action in progress was happening — it does NOT interrupt it: "I was watching TV when Jim knocked the door" (the knock doesn't stop the watching, it just marks the moment).

Until means the second action DOES interrupt and stop the action in progress: "I was playing a game until the electricity went out" (the game stopped).

While means two actions were developing simultaneously, side by side: "She was cooking while he was setting the table."
Common mistake: "I was at home this weekend" ❌ — This describes where you were, not what you were doing. Use Past Simple: "I stayed at home this weekend." ✓

Word Order: When vs. While

When vs While — 'when' + short action (Past Simple), 'while' + long action (Past Continuous), with all 4 word-order variations

'when' + short action (Past Simple tense)
'while' + long action (Past Continuous tense)

I was watching TV when Jim knocked the door.
PatternExample
[long action] + when + [short action]I was watching TV when Jim knocked the door.
When + [short action], + [long action]When Jim knocked the door, I was watching TV.
[short action] + while + [long action]Jim knocked the door while I was watching TV.
While + [long action], + [short action]While I was watching TV, Jim knocked the door.
Comma rule: If the "when"/"while" clause comes FIRST in the sentence, put a comma before the main clause. If it comes SECOND, no comma is needed.

Signal words

when while as at this time yesterday at 10 p.m. last night all day / all morning this time last year

Exercises

Exercise 1 — Fill in the blank

Use the Past Continuous form of the verb in brackets.

1. It (rain) when I left work.
2. What (you / do) at 8 last night?
3. He (not / listen), so he missed the announcement.
4. They (talk) for hours.
5. While she (cook), the phone rang.

Exercise 2 — Past Simple or Past Continuous?

Choose the correct form.

1. I _____ TV when the lights went out.

2. While she was sleeping, someone _____ the window.

3. At midnight, they _____ in the garden.

4. _____ your keys this morning?