English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.
Sign up to join this community
In the following paragraph, I got corrected in that apparently I should've used "find" instead of "found".
I was able to learn more about myself when my parents divorced. I started writing letters to my mother, telling her about my illnesses with the most beautiful words I could {found,find}.
I just want to know what would be the rule for such correction?
"Could" is a modal verb. It modifies the meaning of another verb, which has to be in bare infinitive form (in other words, infinitive without "to").
"Find" is an infinitive form of verb meaning "to discover by searching, to obtain".
"Found" could be:
However, "the most beautiful words I could set up" doesn't quite make sense in your context, and neither does "the most beautiful words I could make by pouring molten metal". So, you indeed should have used "could find".
The modal verb, can is already in its paste-form: could. So you don't need to change also find.
For example, if you say a question about something in the past, you would say:
Why didn't you write that letter?[*]
Or even just a negation:
He didn't write the letter!
The modal verb gets the past-form, where the verb is in its infinite.
At the end of this page you can find more details about the rule.
[*] This statement makes sense if the narrator can't write that now.
