thank you.
I put a song onto my facebook and my friend thanked me. We share the same favorite song.
If your friend thanks you, you say "You're welcom
e".
Here 'welcome' is an adjective, as it is in "You are welcome to listen to my song; you are welcome to my home"
But 'welcomed' can be used as a past participle. "On your arrival at the hotel, you will be welcom
ed by our concierge." This is part of the verb, not an adjective.