2714: Comparing Asleep and On Fleek May 26

There is a prefix a-, found in many verbs, that carries meanings related to away, up, on, or out, as in ‘arise’, ‘awake’ or not as a verb in ‘afoot’ or ‘aside’, but is probably more typically used for conditions of something ongoing, like ‘aglow’, ‘asleep’, and ‘asunder’. This originates from the word ‘on’ and functions similarly as verbs with the on-prefix. It can be used in some other ways too, but the prefix is generally considered non-productive, which is to say that it is not applied onto words aside from a set list now. 

On still does carry the meaning of condition as seen in phrases like ‘on fire’ (compare ablaze) but while it is rare, the prefix a- might still be understood as generative if usually humorous and informal, like “I’m busy a-working”. In the perhaps now outdated slang term of the last decade “on fleek”, or more common “on point” or to have something “on lock”, on has taken on some renewed vigor again in the sense of condition (of). This is not enough to make it productive, it does show that there is some mileage in a conditional-on.