Learn Dutch: We werken van negen tot vijf uur. - We work from nine to five o'clock.

You use the prepositions van (from) and tot (until/to). Just wrap them around the start and end times to show how long something lasts: van negen tot vijf (from nine to five).

Why is the word uur only used at the end? Shouldn't it be van negen uur tot vijf uur?

You actually can say van negen uur tot vijf uur, but Dutch speakers usually drop the first uur to avoid repeating it. It is perfectly natural, just like saying "from nine to five o'clock" in English.

Can I drop the word uur entirely?

Yes! If the context is obvious (like standard working hours), you can simply say We werken van negen tot vijf.

What happens to the word order if I start the sentence with the time?

Dutch uses the verb-second rule. If you put the time phrase at the beginning, the verb werken must come exactly second, before the subject we. It becomes: Van negen tot vijf uur werken we.