Neither. Posy doesn`t exist in German.
Informal? semi-formal
Formal.
Yes, it is. It is the opposite of the word formal (not formal), and a synonym of casual or unofficial.
If you mean 'you': tu (informal, singular); usted (formal, singular) vosotros/as (informal, plural); ustedes (formal, plural)
semi
No, 'nowadays' is an example of informal language.
usted ... or tú (informal) Also consider: Singular: "usted" (formal) or "tú" (informal) or "vos" (Chile, Argentina, Uruguay and some Central-American countries). Plural: "ustedes" (America formal and informal plural; only formal in Spain) or "vosotros" (informal plural in Spain; religious in America).
The German word for you is Du (singular, informal), Ihr (plural, informal), Sie(singular and plural, formal)
A memo is by it's nature an informal communication dispersed among a group of people. However, there is both a formal and a more informal way in which to word the salutation and body of the memo.
it is an informal group
tú = you (informal) Usted / Ud. = you (formal)
'vous' is used as the formal you. It is also used as the plural of 'tu' which is the singular, informal 'you'.