grunt server error in npm even after grunt install successful

I need to run the grunt server command.. but the problem is i am getting the error.. i even installed grunt by using this command npm install grunt and it was successful but i am still getting the error..when i do *grunt serve*r.. can you tell me how to fix it

 grunt sever
Warning: Task "sever" not found. Use --force to continue.

Aborted due to warnings.


Execution Time (2014-03-18 02:16:16 UTC)
loading tasks  1.9s  ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 100%
Total 1.9s