Thank you very much for all your kind answers and encoraugement.
Woody, you're right Despite the fact that i've been playing for years with irish musicians - very few - in Madrid, my girlfriend is english - mancunian - and english languaje teacher, too. I sometimes mess my brain thinking in spanish and speaking in english & vice versa; she laughs a lot with my mistakes, sure my written english is better than the spoken one...
Changing subject, concertina is indeed a very rare instrument in irish sessions in Spain. You can find lots uf flutes, whistles, bouzoukis & uilleann pipes , but very few free reed instruments. So, between button accordion and concertina, finally I decided to choose the last one because I like very much its sweet tone.
I hope learn a lot from all you more experienced players.
Best regards.