Are both okay:

You’re very beautiful now but I can/could tell you were even more gorgeous when you were younger.

anon006Are both okay?

Yes, but they don't mean the same.

anon006I can tell

present thought.

anon006I could tell

past thought.


In either case this is called a left-handed (or backhanded) compliment. Emotion: wink

(Well, that's my assessment of it anyway.)