Seashell has no translation directly, However the generally accepted term is:
Cragen-Mor.
(craa-gen more)
It is possible and valid to say "pick a seashell", or you could try "choose a seashell", if you'd prefer. One example - "Mitch Longley wanted to pick a seashell on Bayley Beach for one of his gorgeous girlfriends."
"You are Welsh" = Rwyt ti'n Gymreig
'Our Friends' in Welsh is 'Ffrindiau Ni' :)
To say "your house" in Welsh, you would say "eich tŷ".
Cymraeg
No in Welsh is dim.
"y diwedd" is how you say it in Welsh language.
In Welsh, you would say "Rwy'n cytuno" to say "I agree."
Draig Gymreig
You can say "it's nice" in Welsh as "mae'n braf."
in welsh its 'mae croeso'
Teisen gri