Did you find it?
It’s the missing subjunctive mood.
“I wish I were traveling in Europe.”
Subjunctive mood is a technical term referring to the form of verb that we use to convey doubt, uncertainty or unrealness. In English, we mostly use subjunctive when we talk about desires, wishes or conditions that are not real. It usually turns up in dependent clauses. This a tough one to spot in English because the subjunctive form for many verbs looks the same as past simple tense.
“I had cake.” (past simple, had)
“If we had cake, we would be eating it.” (subjunctive mood, had)
Subjunctive, specifically, should look just like the second-person singular past simple (past tense verb for you), which is why we should use “were” (second-person singular past simple) and not “was” (first-person, third-person singular past simple.)
“You loved swimming when you were a kid.” (past simple)
“If you loved studying like you love swimming, you would get better marks!” (subjunctive)
“She was a brilliant scientist.” (past simple)
“I wish I were as dedicated to my research as she was.” (subjunctive)
The good news?
The verb “to be” is practically the only verb that isn’t the same for all conjugations. So that means, even if you are still struggling to understand the subjunctive, if you memorize that you should use “were” for unreal conditions (“I wish” and “If” phrases), you will be fine!
http://www.grammarly.com/blog/2014/there-is-one-glaring-error-here-make-sure-you-can-identify-it/
