Can I give someone who had earned income a gift of $xx to put in an IRA for 2018?

[ANON4]

When they file taxes can they claim that $xx (below $5500) contribution as a deduction to reduce their AGI? 

[Anita01]

You can certainly give someone a gift but it will not count towards the amount of income that can be used to make a deductible IRS contribution.  Only earned income counts for a deductible IRS contribution, and a gift is not part of earned income.  If they have enough earned income to cover the contribution they want to make, though, it does not matter whether the money itself comes out of the gift or the income.