Answer:
The coffee isn’t ever hot.
Step-by-step explanation:
Double negatives in a sentence are when a statement contains two negative elements or words like in the given sentence "isn't" and "never". In correct English, we do not tend to use it because they are confusing. In order to correct the sentence, either of the negative elements needs to be removed, this would be the result:
The coffee is never hot
The coffee isn't ever hot