How do you say 'You're welcome MrsCasselle' in Spanish?

Answer 1

If you mean a response of a statement or action, you could say "De nada" or "por nada" (de nada, señora Casselle). Literally this is "it is nothing", but would be translated as "you are welcome" in English.

If you mean a greeting to a place, as in "welcome to my house", then it is "bienvenido" (bienvenido a mi casa, señora Casselle). This is a combination of "bien", meaning "well", and the past participle of "venir" (venido), which means "come". Literally translated to English, this is "well come".