Which coordinating conjunction is used for contrast?

The coordinating conjunction 'denn' is used to give an explanation or reason for a stated fact or action. Therefore, in this context 'denn' is the best fit as it explains why the person couldn't sleep (because they had a lot of coffee).

• Coordinating Conjunctions

The coordinating conjunction 'denn' is used to provide a reason or explanation for the action or state described in the main clause. In this case, the desire to buy milk is explained by the fact that there is no milk at home. Note - 'weil' can also fill this role, but doesn't fit in this sentence grammatically as the verb would need to move to the end.

• Coordinating Conjunctions

The coordinating conjunction that is used to show a contrasting idea or correction is 'sondern', which means 'but/on the contrary'. 'Sondern' is used specifically after a negation to introduce an alternative or a contrasting statement, implying a correction or refinement of what was negated. It's similar to "but rather" or "but instead" in English.

• Coordinating Conjunctions