(someone) has to (do something)

When you say that you "have to" do something, it means that you must do it.

I have to work on Saturday.

But "must" is very formal. It's usually used for written instructions or commands, but not in spoken conversation.

Daddy

"Daddy" is the name that many young children call their fathers. They start to use the name "Daddy" at about 2-3 years old and keep using it until about age 10-13. As children get older, they start to use the name "Dad" instead of "Daddy".

When parents speak to very young children, from 0-5 years, they often speak about themselves as "Daddy" or "Mommy" instead of using "I" and "me". For example:

Daddy doesn't like it when you throw your toys.

Of course, there's a lot of variation from family to family in what children call their parents and how parents refer to themselves. 

(someone) goes to work

"Going to work" means leaving your house to go to your workplace.

It's a lot more common to say "go to work" than "go to my work", "go to my job", "go to the office", or other choices.

tiger

"Tiger" is an affectionate name that fathers sometimes call their sons.

For example:

All right, tiger, it's time for bed!

You did a great job today, tiger!

Mothers don't use this name as often. It's not very common for parents to call a daughter "tiger" either.