Translation of verfallen

Please take into account, that on May 10 and 11 there are holidays in the United States and that we do not work on Saturday. This will leave only the 15th, 16th and 17th for a company visit.
In plural there is no difference between the formal and the colloquial address form. Do you mean that you are using 3rd person singular form for the plural imperative? If so, I will change all entries so far.
I do not teach Spanish, but geography and history at a school here in Frankfurt. It is good to live for a year in another country. I would be glad to receive a picture of you.