Which sentence is correct? 1. Donna is taller than I. 2. Donna is taller than me. No one at school is sure about this answer.

Donna is taller than I.

If you say it from your perspective you would say:

I am taller than Donna.
Not,
Me is taller than Donna.

er woops, i mean

I am shorter than Donna.
not, Me is shorter than Donna.

Good job, Anonymous...

"than I" is part of an adverb clause. What is left out is "am". And, you certainly would say, "me am" <G>