Should I use a singular or plural noun with decimals below 1? Is it correct to write 0.5 hour? Or, is it 0.5 hours?
In Practical English Usage (1995), Michael Swan tells us that singular nouns are generally used with decimals (and fractions) below 1. For example:
Decimals (and fractions) over 1 are followed directly by a plural noun, as in the following examples: