Choose the correct form of Tense for words given in brackets :
I wonder if anything (happen) to Tom. I (wait) an hour now. He often (keep) me waiting, but he never (be) quite so late as this.

Question

Choose the correct form of Tense for words given in brackets : 
I wonder if anything (happen) to Tom. I (wait) an hour now. He often (keep) me waiting, but he never (be) quite so late as this.

Accepted Answer

Here's a detailed explanation justifying why Option 2 is the correct answer and why the other options are incorrect:

**Why Option 2 is Correct: "has happened, have waited, has kept, has been"**

Option 2 provides the most grammatically correct and contextually appropriate tense sequence for the given sentences. Let's break it down:

*   **"has happened"**: "I wonder if anything *has happened* to Tom." The present perfect tense ("has happened") is used to express an event that occurred at an unspecified time in the past but is relevant to the present. The speaker is concerned *now* about something that *might have happened* to Tom in the past. This tense implies a possible past event with present consequences (Tom's absence).

*   **"have waited"**: "I *have waited* an hour now." The present perfect continuous tense ("have waited") is used to describe an action that started in the past and is still continuing in the present. The speaker began waiting an hour ago and is *still* waiting. This tense emphasizes the duration of the waiting.

*   **"has kept"**: "He often *has kept* me waiting..." The present perfect tense ("has kept") is used to describe an action that started in the past and is still continuing in the present. The speaker began waiting an hour ago and is *still* waiting. This tense emphasizes the duration of the waiting.

*   **"has been"**: "...but he never *has been* quite so late as this." The present perfect tense ("has been") is used to describe an action that started in the past and is still continuing in the present. The speaker began waiting an hour ago and is *still* waiting. This tense emphasizes the duration of the waiting.

**Why Other Options are Incorrect:**

*   **Option 1: "had happened, had waited, keeps, was"**
    *   "had happened" and "had waited" are in the past perfect tense. While grammatically correct in some contexts, they imply that these actions were completed *before* another past action. This doesn't fit the context, as the speaker is still concerned and still waiting.
    *   "keeps" is in the simple present tense. While "He often keeps me waiting" is grammatically correct on its own, it doesn't flow logically with the rest of the passage, which focuses on the *current* situation.
    *   "was" is in the simple past tense. "He never was quite so late as this" implies a completed state in the past, not a comparison to the present situation.

*   **Option 3: "will happen, will wait, will keep, will be"**
    *   All the verbs are in the future tense. This completely changes the meaning of the sentences. The speaker is not wondering about something that *will* happen, but about something that *might have already happened*. The speaker is not planning to wait, but *is currently* waiting.

*   **Option 4: "could happen, could wait, can keep, can be"**
    *   These verbs use modal verbs (could, can) which express possibility or ability. While grammatically correct in some contexts, they don't convey the intended meaning. The speaker isn't saying that something *could* happen, but expressing concern that something *has* happened. The speaker isn't saying that Tom *can* keep them waiting, but stating that he *often does*.