7.2c En as contraction for enough. [XII.38.d]

The whole-word contraction en cannot be used for anything other than the word enough. When the letters en form part of an anglicized expression or a name such as en route, en masse, Chou En-Lai or Aix-en-Provence the contraction cannot be used, and the letters must be spelled out.

When the word enough cannot be contracted because it is in contact with punctuation, the en contraction (to be studied next) is used. (Enough! )