how to know if a row has a foreign key on other table

how to know if a row has a foreign key on other table

hi guys i've been searching and trying with no luck for a solution
regarding my two tables in an ms sql 2008 r2 my tables are below:
table 1 pk personid varchar - i manually insert here from GUID fname
varchar mname varchar lname varchar qualifier varchar
table 2 pk id - increment by 1 fk personid varchar salary int deductions
int salary_month int salary_year int
now my aim here is to know which entries have a foreign key on the other
table if not i want to delete it
i really need some help i have been trying it for a couple of weeks