Past continuous - I was doing, I did

The past continuous (was/were + -ing) describes actions that were in progress at a specific time in the past. The simple past (I did) describes completed actions or events that happened at a specific time. We often use both together: the past continuous gives the background or ongoing action, and the simple past describes a shorter action that interrupts or completes the background.

• Past continuous: was/were + verb-ing → ongoing action in the past (background).
• Simple past: verb in past form → completed action or specific event.
• Use both together: 'I was working when the client called.' (background + interruption).

Use the past continuous for actions in progress. Use the simple past for actions that happen once or interrupt.

• Past continuous: 'I was + -ing' → describes what was happening.
• Simple past: past verb (e.g., 'I finished') → describes completed events.
• Combine: Past continuous + when + simple past → ongoing action interrupted by a single event.

Remember: background (was/were + -ing) → interruption (simple past)

Learners often make predictable errors when using past continuous and simple past. Watch out for these universal mistakes:

• Using past continuous for completed actions: 'I was finished the report.' (incorrect).
• Forgetting the auxiliary 'was' or 'were' with -ing: 'I writing' (incorrect).
• Using past continuous with stative verbs (believe, know, like) when simple past is needed.
• Mixing time markers incorrectly: using 'yesterday' with a very specific completed sequence where simple past is clearer.

Check auxiliary + -ing for past continuous and use simple past for completed or interrupting actions.