Final answer:
All compound numbers from twenty-one through ninety-nine are indeed hyphenated, which clarifies that they are single entities and not two separate numbers.
Step-by-step explanation:
The statement regarding hyphenation is True. In English, all compound numbers from twenty-one through ninety-nine should be hyphenated. This includes any number that is made up of two words, such as 'thirty-six' or 'eighty-four'. The hyphen connects the two parts of the compound number, which makes it clearer that the number is a single entity and not two separate numbers. For example, 'sixty-two' is written with a hyphen to differentiate it from simply the two numbers 'sixty' and 'two'.