No.
Your child over age 18, must be a FULL TIME student for parts of 5 calendar months to be considered a Qualifying Child Dependent*.
The half time student rule is about the course work qualifying for an education credit. It is not about dependency qualification.
*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/student status test. Your adult child may still qualify as a standard dependent if his income for the year was less than $4050.
