I have a daughter who turned 24 during 2019 so I cant claim her as a dependent. If I paid part of her tuition, can I use the Lifetime Learning credit (I used the American Opportunity credit the previous 4 years).?

[CatinaT1]

If you are not claiming her, no, you would not be able to claim the expense.

[Hal_Al]

Your daughter can count the money, you paid, in claiming the Lifetime Learning credit (LLC) on her return.

If she has less than $4200 of income, in 2019, you may still be able to claim her as a dependent. There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, a relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income Credit.

Because she is 24, now, sh can no longer be a QC.  But, A person can still be a Qualifying relative dependent, if not a Qualifying Child, if he meets the 6 tests for claiming a dependent:

1. Closely Related OR live with the taxpayer ALL year   (not even one night at the non-custodial parent’s home).
2. His/her gross taxable income for the year must be less than $4200 ($4150 in 2018)
3. The taxpayer must have provided more than 1/2 his support

In either case:

4. He must be a US citizen or resident of the US, Canada or Mexico
5. He must not file a joint return with his spouse or be claiming a dependent of his own
6. He must not be the qualifying child of another taxpayer