mee SAY man-KAH-toh TAN-toh doo-RAN-tay
Here's a breakdown:
* Mi: Pronounced like "mee"
* sei: Pronounced like "say"
* mancato: Pronounced like "man-KAH-toh"
* tanto: Pronounced like "TAN-toh"
* durante: Pronounced like "doo-RAN-tay"
The stress is on the second-to-last syllable of each word.
The sentence translates to "I missed you so much during..."