4a. John has become a rather good actor.
4b. John has became a rather good actor.
John BECAME (past tense) or HAS BECOME (Present Perfect)
has become
The correct sentence is 4a: "John has become a rather good actor."
In English, the past form of the verb "become" is "became." However, when using the present perfect tense, we use the past participle form of the verb, which is "become" in this case. So, we would say "has become" instead of "has became."
To verify this, you can follow these steps:
1. Identify the verb in the sentence, which is "has become."
2. Determine if it is in the past tense or present perfect tense.
3. For the present perfect tense, use "has" or "have" (depending on the subject) followed by the past participle form of the verb.
4. In this case, "has become" uses the present perfect tense correctly because "has" agrees with the subject "John," and "become" is the past participle form of "become."
Therefore, the correct sentence is "John has become a rather good actor."