By Warm regards, Plurals

Dear Taka, It is perhaps similar to «change horses». It is plural perhaps because there must be two trains. Warm regards, Goldmund

Thanks CalifJim for your help. Actually I am a non-native speaker of English. The problem with non-native speakers is they translate their language to English and sometimes what we think is correct in our own language may not be correct while translating. In my language, we don't use ANY with...