I should like to reassure your correspondent Paul Wood (Journal Postbag, December 13) that there is nothing grammatically wrong with the sentence "Intermittent lighting during darkness hours" (allowing for the fact that it has no verb).

I agree, it sounds a little odd, perhaps because the phrase "darkness hours" is not commonly used.

The phrase "daylight hours", for example, might jar rather less.

Mr Wood is of course right to say that "darkness" is a noun, but in this context it is a noun being used as a modifier, what is called an ascriptive noun, and Mr Wood's chosen alternative "hours of darkness" explains the meaning intended.

Examples of the noun "Christmas" being used as an ascriptive noun abound at this time of year.

So there is no need to despair for the language.

Christmas greetings,

Roger Dismal.