If clause, when embeded

I think it goes like " I'm not sure If he will give 50% of his salary to his parents when he earns $10000 a month"

@Su's posted:

I think it goes like " I'm not sure If he will give 50% of his salary to his parents when he earns $10000 a month"

Thanks Su's . Do you think I can simply use "whether" to avoid repeating "if"？

@Robby zhu posted:

Hi.

- If he earns $10000 a month, will he give 50% of it to his parents?

If I want to make the sentence above a subordinate clause in the construction "I'm not sure if...", should I substitute "when" for "if":

I'm not sure if ( if/when he earns $10000 a month, he will give 50% of it to his parents).

I think that the compound "if if" doesn't sound right. And is there any other options？ Thank you.

Hello, Robby zhu—Yes, avoid using "if if," which would be stylistically horrid. But don't use "when"; that presupposes he'll make that much. You can say:

(1) I'm not sure whether, if he earns ten thousand dollars a month, he will give fifty percent of it to his parents.

(2) I'm not sure if he will give fifty percent of his monthly earnings to his parents if he earns ten thousand dollars a month.