Yes it should be hyphenated.
no hyphens - 57 years old is what you are.
Most people would spell it sixteen-year-old child. But over the last 20 years, people are ignoring the hyphens.
It's unneccesary, but you can say 7-year-old boy to make it one word. Just hyphenate any place where you would normally see a space.
like whatever the 11 year old likes
does he like 12 year old girls
No! how is it wrong to like a eighteen year-old??
A person can like a 17 year old. You cannot help who you like.
NO
People have any number of personal reasons to like whoever they like. If a 17 year old boy liked a 14 year old girl, his reasons are his own.
You cannot make 12 year old look like 10 year old. You can do makeup to hide the age.
Yes. A twelve year old friend of mine babysat a 5 year old for like 3 hours and did great. She is like most 12 year olds and is VERY trustworthy.
The 10 year old will most likely act like they normally do