When we write any verb in Spanish with 'I' then we mention 'o' at the end of the word. Eg. - 'Yo bebo la leche'. Similarly when we use any verb after 'Usted' then the verb (as i have seen) ends with 'e' . Eg. 'Usted come una manzana'. So when we write - You are welcome in Spanish then we write 'Usted es bienvenido'. Why don't we write 'Usted es bienvenide' with 'e' at the end of bienvenido instead of 'o'???