Lens for my nikon D5000?

Is their an af-s 50mm f/1.8 for the nikon d5000?

No, only an af-s 35/1, 8

No.

The 50 mm AF-S is the f/1.4.

If you don't mind going "old school" and manually focusing your shots like most portrait photographers did before the advent of fast, dependable auto-focus, the AF 50 mm f/1.8 is a fine lens. Just use the electronic rangefinder in the cameras viewfinder to assure sharp focus (the green dot stays on when you are in focus)