Remember that the Past Simple is formed by adding '-ed' to regular verbs, or using the irregular past tense form. For negative sentences, we use 'did not' (didn't) + the base form of the verb. For questions, we use 'Did' + subject + base form of the verb.
1. I went (go) to the zoo last week. (Irregular verb 'go' in Past Simple is 'went').
2. Did you see (see) a new film with Daniel Radcliff? (Question form, 'see' is the base form).
3. We didn't watch (not watch) TV yesterday. (Negative form, 'watch' is the base form).
4. Did you finish (finish) your work? No, we didn't. (Question form, 'finish' is the base form. The second part of the sentence implies a negative answer for 'we').
5. They played (play) football last summer. (Regular verb, add '-ed').
6. Did she visit (visit) Paris last year? - No, she visited (visit) London. (Question form, 'visit' is the base form. The answer uses the Past Simple 'visited').
7. My friends didn't surf (not surf) the Net yesterday. (Negative form, 'surf' is the base form).