Are you younger than full age retirement and make more than the yearly earnings limit?
No.
but what if I'm under full retirement age during the full year before full retirement age?
then you'd get deducted 1$ for every 2$ you make above the yearly limit. The yearly limit for 2019 is 17640$.
What its the full retirement age?
66 for those born between 1943 and 1954. And from 1955 onwards, two months are added for every birth year until the full retirement age reaches 67 for people born in 1960 and later.
So I can actually keep my benefits while working, even if with a deduction, right?
Yes, that's correct.
What's the earning yearly limit again?