I want to know ________ he is always

[keannu]

The answer for the blanks is 1, but doesn't 3 also work?

*Michael always smiles at people. I want to know ________ he is always in a good mood.
*Have you lost your watch? I'll tell you ________ I find it.
1.if - if 2.that - if 3.how - when

 

[bhaisahab]

The answer for the blanks is 1, but doesn't 3 also work?

*Michael always smiles at people. I want to know ________ he is always in a good mood.
*Have you lost your watch? I'll tell you ________ I find it.
1.if - if 2.that - if 3.how - when

Neither one works very well.

 

[emsr2d2]

The answer for the blanks is 1, but doesn't 3 also work?

*Michael always smiles at people. I want to know ________ he is always in a good mood.
*Have you lost your watch? I'll tell you ________ I find it.
1.if - if 2.that - if 3.how - when

1 makes no sense for the first. It gives:

Michael always smiles at people. I want to know if he is always in a good mood.

Whilst not entirely ungrammatical, it doesn't make any sense. If someone always smiled at people, I would want to know why he was always in such a good mood. At a push, I would wonder how [it was possible] that he was always in a good mood.

With the second sentence, "if" and "when" both fit.

Of the three, #3 is the least wrong answer but I think it's a bad test question.