- $this->showForm(sprintf(_('That\'s too long. ' .
- 'Max message size is %d chars.'),
+ // TRANS: Form validation error displayed when message content is too long.
+ // TRANS: %d is the maximum number of characters for a message.
+ $this->showForm(sprintf(_m('That\'s too long. Maximum message size is %d character.',
+ 'That\'s too long. Maximum message size is %d characters.',
+ Message::maxContent()),