Mein Alltag: telling the time, prepositions ‘um’, ‘seit’ and ‘vor’

Use the 12 hour or the 24 hour clock to tell the time in German. Use 'um' to say ‘at’ with clock times. 'Um' can also mean ‘around’ or ‘approximately’ when used with numbers, and is normally followed by the definite article. When referring to a place, 'um' means ‘around’ and is always followed by the accusative case. 'Seit' is used with present tense to express an unfinished action started in the past. It can mean ‘since’ or ‘for’. 'Vor' + length of time is used with past tense to say how long ago something happened. Use the dative case.