subjunctives - "I would love to if I can" vs. "I would love to if I could"

• I would love to if I can
  


• I would love to if I could

Which one is right?

Answer

I would love to if I could has CAN in the past tense but with present reference as a counterfactual:

SHE: Hey, Marco, we're going to the Thai place for lunch, you wanna come with?
YOU: I'd love to if I could, but I'm waiting for a call.

I would love to if I can has CAN in the present tense but with future reference as a contingent possibility:

SHE: Hey, Marco, we're going to Spiro's after work, you wanna come with?
YOU: I'd love to if I can, but right now I don't know how late I'm gonna hafta work.