Past simple auxiliary verbs
Did and didn't are used as past simple 'helping' verbs in exactly the same way as do/don't and does/doesn't are used in the present simple.
Study the following examples:
- 'I played a lot of rugby as a young man, but I didn't ever play football.'
- 'You didn't forget to post my letter, did you?' 'Of course I didn't.
- 'Did he pass his exam?' 'He did, yeah!'
- 'I did remember to put salt into the dishwasher. It's not my fault that it's not working.'