simple Haskell loop

I just started learning Haskell, but the absence of loops is infinitely frustrating right now. I figured out how to write loops for functions. My problem, however, is that I want to output some results while iterating the loop. It seems that I have to use debug to perform this simple task.

So right now I would just appreciate an example of how to print out a string 10 times in the main structure.

In other words, I want to do this 10 times:

main = do  
    putStrLn "a string" 

Thanks. I feel this will be very illuminating for my task.