Do scholarships or school grants count as unearned income ? Im not sure why I need to fill out form 8615 when I earned income more than one-half of the support?

Q. Do scholarships or school grants count as unearned income ?

A. Yes, for purposes of the kiddie tax and the need for form 8615.

Scholarships are a hybrid between earned and unearned income. It is earned income for purposes of the $13,850 filing requirement and the dependent standard deduction calculation (earned income + $400).  It is not earned income for the kiddie tax and other purposes (e.g. EIC).  For grad students and post grad fellows, scholarship, stipend and fellowship income is earned income ("compensation") for IRA contributions.

So, even though form 8615 may be required, you'll need more than $13,850 of income before any actual tax kicks in.

Scholarships are not earned income for the "did half your support come form your own earned income" test. That test determines whether you're subject to the kiddie tax and may affect whether you can be a dependent.