On second thoughts, is it possible to really think foreign? Except perhaps for ones who have lived abroad for years, I mean?

It`s not just language, it`s the environment and things... Can a Scandinavian think like an African? Can Orientals truly understand westerners, and vice versa? Is it possible to translate without that kind of deep understanding?

Well, good translations happen, so it seems to be possible. Is it because

?

Still, I`m in doubt...

I voted to think both seems like I am a Bilingual. FYI, Bilingual person is often think both the languages because the person tend to code-switch. Anyway, there is no right or wrong if you think what language, but I strongly agreed, if you want to improve English, just keep on thinking in English.

Thank you,

 "Bilingual" is a convenient word because it carries two slightly different meanings:

One of the above definitions implies fluency, the other not necessarily.

bilingual: using or able to use two languages especially with equal fluency
http://www.merriam-webster.com/dictionary/bilingual

"Especially" implies not necessarily.

Using or able to use two languages, especially with equal or nearly equal fluency.
http://www.thefreedictionary.com/bilingual

Containing, or consisting of, two languages
http://thinkexist.com/dictionary/meaning/bilingual/

In linguistics, code-switching is the concurrent use of more than one language, or language variety, in conversation. Multilinguals—people who speak more than one language—sometimes use elements of multiple languages in conversing with each other. Thus, code-switching is the use of more than one linguistic variety in a manner consistent with the syntax and phonology of each variety.

Code-switching is distinct from other language contact phenomena, such as borrowing, pidgins and creoles, loan translation (calques), and language transfer (language interference). Speakers form and establish a pidgin language when two or more speakers who do not speak a common language form an intermediate, third language. On the other hand, speakers practice code-switching when they are each fluent in both languages. Code mixing is a thematically related term, but the usage of the terms code-switching and code-mixing varies. Some scholars use either term to denote the same practice, while others apply code-mixing to denote the formal linguistic properties of said language-contact phenomena, and code-switching to denote the actual, spoken usages by multilingual persons. ^{[1][2][3][Read More]}

That article is playing, then, on the same ambiguity I pointed out before, without clarifying it. For example, I "speak" Spanish because I can read it but I would be unable to converse in it. So I am, er, "bilingual" (and even "multilingual") but my code-switching between Polish and Spanish is scarce.