I need help putting a few words into the dative case.

1)parvus puer
2)rex fortis
thank you in advance

puer = 2nd declension

So dative is puero.
Now make the adjective match. What will you have?

rex = 3rd declension
So dative is regi.
Now make the adjective match. What will you have?

http://www.math.ohio-state.edu/~econrad/lang/latin.html