Student or Learner
Q - Mom, where is my watch?
A1 - It must be in the drawer.
A2 - It should be in the drawer.
In what context would it be preferable to use A1 or A2 as an answer to the question above?
If you use the first one you have probably looked for it in other places and haven't found it. If you use the second one you are probably talking about the place where you would normally expect to find it.
A: Mom, I can't find my watch.
B: It should be in the drawer.
A: Which drawer?
B: The top dresser drawer.
A: Why would it be in there?
B: That's where I put it when I found it on the floor.