Antonyms
Antonymy involves opposition of meaning, which can take a variety of forms. In the case of gradable antonyms, for example long and short, to affirm one member of the pair is to negate the other:
X is short entails X is not long
X is long entails X is not short
An important property of gradable antonyms is that negation of one does not entail the other, i.e. ‘not tall’ does not entail ‘short’: it is perfectly possible to be neither. They can be used in sentence frames of the ‘X is Y-er than Z’ type, and are distinguished from non-gradable antonyms or complementaries (e.g. alive/dead; true/ false) in that, for the latter, negation of one does entail the other:
X is not true entails X is false
X is not dead entails X is alive
Another kind of antonymy involves what are known as relational opposites. If I give you something, then you receive it; if John is Paul’s teacher then Paul is John’s pupil, and so on. Finally, there is the antonymy of reversives, in which one form means not the negative of the other, but its reverse: examples here include enter/exit (or entrance/exit), remember/forget, tie/ untie and so on.
