need help for buying a lens

need a new lens for portraits nature and sport, but which one is te best.
Canon EF 50mm f/1.4 USM
Canon EF 85mm f/1.8 USM

Camera is the Canon 500D...

Both are great lenses.

For some the 85mm. is a bit to long on a crop body, but only you can determine that. If you work in a small studio, you may not have enough room to use it for anything other than head shots.

I would also consider the sigma 50mm. f/1.4
It may just be me, but I would choose that one over the canon equivalent, any day.

For most sports you would most likely want something in the telephoto range. So the 85mm. would be a decent choice. If you can get close enough though, the 50mm. would do just fine.

For nature, it really depends on what you want to shoot.
For landscapes, you might want something wider than 50mm. and for birds and wildlife, a longer focal length will come in handy more often than you might think.

and this one, Canon EF 28-105mm f/3.5-4.5 II USM is that better or Canon EF 50mm f/1.4 USM.

I would consider the SIgma 50 F1.4, as the Canon f1.4 has history of AF motor problem.
The 85 F1.8 is excellent for sport and good for portrait also ( 135mm equiv on crop )