2. My son is too young to live alone

=> My son is so young that he can't live alone

=> My son isn't old enough to live alone.

3. This movie is too boring for us to see

=> This movie is so boring that we can't see

=> This movie isn't interesting enough for us to see

4. That book is too bad for you to read.

=> That book is so bad that yo can't read

=> That book isn't good enough for you to read.

5. These shoes are too small for her to wear

=> These shoes are so small that she can't wear

=> These shoes aren't big enough for her to wear

6. Nam is too weak to become a policeman

=> Nam is so weak that he can't become a policeman

=> Nam isn't strong enough to become a policeman.