Explanation:
Logic: The task requires identifying the base form (infinitive) of the verb given its past simple and past participle forms. This is a common exercise in English grammar to test knowledge of irregular verbs.
Solution:
- The given forms are 'spoke' (past simple) and 'spoken' (past participle).
- These are the irregular past forms of the verb 'to speak'.
- The first form (infinitive) of this verb is 'speak'.
Answer: speak