How do you report tuition and expenses for 2019 Semester paid for by a portion of scholarships reported in the 2018 form 1098-T, but not in the 2019 form 1098-T

The 1098-T is only any informational document. The numbers on it are not required to be entered onto your tax return. However receipt of a 1098-T frequently means you are either eligible for a tuition credit or deduction or possibly your student has taxable scholarship income. 

If you claim the tuition credit, you do need to report that you got one or that you qualify for an exception (the TurboTax interview will handle this)

You claim the tuition credit, or report scholarship income, based on your own financial records, not the 1098-T.

 In the 1098-T screen, click on the link "What if this is not what I paid the school" underneath box 1. You will then be able to enter the actual amounts paid.  In your case, you apparently reduce  box 1  by the amount paid in 2018, by the grant.