past tense of modal verbs

Question

Is it appropriate to say, "Bob was not sure whether Kate was at work. She might be at work."?

In my opinion, "Bob thought, 'She may/might be at work.'"is correct.

Switching it to indirect speech, "Bob thought she might be at work." is correct.

So, omitting "Bob thought" without misunderstanding, "She might be at work." is correct.

However, there is another saying that there's no simple past form of "might". We must use "might have been" to refer the the past time.

Could anyone help me out with this problem? Thanks a lot.

Answer 1

"Bob was not sure whether Kate was at work now. She might be at work."

is okay though though rather than mix past was with present now better might be:

1. "Bob was not sure whether Kate was at work when I asked." (all in the past)
2. "Bob is not sure whether Kate is at work now." (all in the present)

You can omit the when I asked/now part.

For another part of your question:

We must use "might have been" to refer the the past time.

I don't think you want to use that:

• "Bob was not sure whether Kate was at work now. She might have been at work."

because then you are using at work now with might have been at work. It's grammatical and I would understand it. But what I would understand is that the second sentence is somewhat disconnected to the first sentence because it appears to reference a much earlier event that the speaker thinks Kate knew about or was involved in. Imagine:

Alice: "The server went down at midnight. Was Kate here then? Is she here now?" Charlie: "Bob is not sure if Kate is at work now. She might have been at work (at midnight when the server failed)."

Your sentence wasn't in context, so whether or not might have been is appropriate or not I can't say.