Help Detective Paws complete his investigation notes about the missing cookies by choosing the correct modal verb for each blank.

The cookie jar is empty and Buster the dog has chocolate crumbs on his nose. He must be the culprit!

However, Whiskers the cat is fast asleep in the other room. She can't be the thief because she hasn't moved from her bed all day.

There is an open window in the kitchen, so a sneaky neighborhood squirrel might be involved, but we need more evidence to prove it.

The cookie jar is empty and Buster the dog has chocolate crumbs on his nose. He must be the culprit!

We use must when we are almost 100% sure something is true based on strong present evidence (the crumbs).

However, Whiskers the cat is fast asleep in the other room. She can't be the thief because she hasn't moved from her bed all day.

We use can't when we are almost 100% sure something is NOT true. If she has been asleep all day, it's impossible that she stole the cookies.

There is an open window in the kitchen, so a sneaky neighborhood squirrel might be involved, but we need more evidence to prove it.

We use might (or may/could) when we think something is possible, but we aren't completely sure.