Numbers and time
Vigesimal numbers and telling time
Can use vigesimal numbers and tell time in Danish
Look at these examples. Can you spot the grammar pattern?
Jeg er halvtreds år gammel, og min mor er firs.
I am fifty years old, and my mother is eighty.
Toget afgår halv ni, ikke klokken ni.
The train departs at 8:30, not at 9:00.
Der er treoghalvfjerds elever på skolen.
There are seventy-three students at the school.
Pay attention to the highlighted parts. What do they have in common?
Vigesimal numbers: halvtreds(50), tres(60), halvfjerds(70), firs(80), halvfems(90). Time: halv ni = 8:30.
The vigesimal number system (50-90) and 'halv' time are the hardest Danish features for foreigners.
🇬🇧 English: 50-90 are completely different. 'Half nine' in British English = 9:30, but Danish 'halv
Common Error Patterns
Confusing vigesimal numbers (halvtreds, tres, halvfjerds, firs, halvfems)
Memorize: halvtreds=50, tres=60, halvfjerds=70, firs=80, halvfems=90. Pattern: halv+X = (X-0.5)×20.
Interpreting 'halv ni' as 9:30 instead of 8:30
'Halv ni' = 8:30 (half TO nine). Like German 'halb neun'. NOT 9:30!
Jeg er halvtreds år gammel, og min mor er firs.
I am fifty years old, and my mother is eighty.
'Halvtreds' = 50 (2.5 × 20). 'Firs' = 80 (4 × 20). The vigesimal system is unique to Danish!
Toget afgår halv ni, ikke klokken ni.
The train departs at 8:30, not at 9:00.
'Halv ni' = 8:30 (half TO nine). This is the #1 time trap for learners!
Der er treoghalvfjerds elever på skolen.
There are seventy-three students at the school.
'Treoghalvfjerds' = 73 (tre-og-halvfjerds = 3 + 70). Units come BEFORE tens, like German!
Practice in course
Apply this grammar in A1 course exercises