English · A2 · verb · 4 minutes
Do: past simple
Use did as lexical past or auxiliary, but keep the main verb base after auxiliary did.
Understand the choice
In did you do it?, the first did is auxiliary and the second do carries lexical meaning. Only the auxiliary is past-marked.
Core rule: Did is the past of do for all subjects and also supports past questions/negatives.
Notice it in context
I did my homework, and she did the shopping.
Hice mis deberes y ella hizo las compras.
Did is lexical in both clauses and stays unchanged across I/she.
What did you do yesterday?
Which activity did you complete yesterday?
Auxiliary did supports question; lexical do is base.
They did not do the work.
They did not complete the task.
Did not carries past/negative; second do stays base.
What to remember
- Did is pronounced /dɪd/ and never changes by subject.
- Emphatic I did finish uses did + base verb.
Common trap: Do not write did you did.