Idioms can be a powerful linguistic tool only when they are used in the right way in the right places.
by the hour
after each hour, one hour at a time
We had to pay for our parking space by the hour.
List of common idioms, their meanings and examples of their usage in sentences
An expression in the usage of a language that is peculiar to itself either in having a meaning that cannot be derived from the conjoined meanings of its elements or in its grammatically atypical use of words.