Yii does not provide a translation message file for the en_us language. Instead, we are expected to rely on the core messages to be correct.
If I was successful in finding where the core messages are held, I still wouldn't want to mess with the core file because, A. it is ill-advised and B. future version revisions would overwrite my changes.
Is my only alternative to copy any other language message file and hand edit every single message so that the translated message is the same as the english message (with my correction(s) in place? It seems like a lot of work for the sake of one word that needs correcting.
The reason I bring this up is this...
If you navigate to a non-existent page, their error message is: 'The requested view "{name}" is not found.' I think it should say: 'The requested view "{name}" was not found.'
I argue that they are mixing tenses in this statement ('requested' = past tense and 'is' = present tense).
Rightly or wrongly, I am 'uncomfortable' with their grammar.