Planting grass under Pine trees?

A better choice (think about having to mow under there) is a ground cover. Violets, lily of the valley, several vining covers, and ferns will all grow in the understory of these types of trees. Some mulch will keep the area neat.

There is grass that will grow in shade. Can't give you a name. Look at the descriptions on the different grass seeds.

Your best bet is probably going to be a ground cover. Google or Yahoo search 'ground cover for shade'. Many, many sources will come up and you can get some ideas. I've always loved Periwinkle and Vinca. Check also whiteflowerfarm.com. They have lots of pictures and you can get lots of ideas.

P.S. Skip the ivy. That can really get out of control.

It's highly unlikely you will be able to get grass to grow in the shade. All those products promoting shady grass seed are mostly gimmicks. Grass needs sun. What will grow in the shade is various ground covers like ivy or pachysandra. I have pachysandra on the shady side of my house and my neighbor has ivy along the same border. Both look nice.

do not put grass here it is too difficult to mow when the needles drop...i would male a border edge with large rock and then throw in some extra dirt and plant...verbena...or something that is a evergreen like the pine and the flowers....look up flowering evergreen photos....you want something hardy...lantana is another but i am on the west coast

The soil under the trees has become acidic from the pine needles. You could lime the soil but it may kill the pine trees. You may want to mulch the area.