>>28
what
Why are you trolling /lang/, you won't get many answers here. If you aren't a troll, you are probably just totally retarded.
Perfekt: Ich habe einen Mann gesehen. (I saw a man) Sounds right and normal. Used in everyday speech by almost everyone. Can be used without any problemes in literature as well.
Präteritum (Imperfekt lolwut, it's actually called Präteritum): Ich sah einen Mann. Sounds somewhat unnatural in normal speech, educated/sophisticated if you want so. Common in literature.
Some of the southern German dialects don't even have any Präteritum (imperfect lol) at all. The Präteritum is still used in the northern parts of Germany, but its importance is declining and the Perfekt is usually prefered. The only verbs that I can think of where the Präteritum is used very frequently are "sein" and "haben".
tl;dr troll
>>29
Your sentence is correct, but you should write "sie" instead of "Sie" since "Sie" implies that you address a person you don't know very well etc. I guess it's already explained somewhere in this thread.