Adding stock loses to taxes

In USA there is normally about 12k deduction for a single person filling taxes. If I have 1k losses in stocks can I take the 12k default deduction + 1k? I know there is a 3k limit to stock losses but I am not sure if I can combine the default 12k and the stock loss.

I think I have 2 options:

1. Take the 12k deduction
2. Have losses over 12k (not stocks) then I can add 1k stock loss.

Could someone explain?