Gender of non German words?
If you are using a non German word what gender would you use? For example you are at McDonalds what would you say "Ich möchte (einen/ein/eine) Bigmac, bitte
This is a very interesting question. Never thought about it and I just googled a bit :)
In general allintolearning is correct. You can often determine the gender from a base word. And yes, you'd say "der Big Mac" and "das McFlurry".
But if you think about it.... it's just a convention between the speakers of a certain language. You get a word (an anglicism, a foreign expression or even a neologism) and then people just decide the gender based on what feels right. But that also means that there are certain foreign words that don't have one specific gender, because the native speakers don't know themselves :)
E.g. for "the laptop", you'll find that Germans may use "der Laptop" and "das Laptop".
On the other hand, you have something like "song". There is a German word for it: "das Lied" (neuter), but "der Song" is also widely used as an anglicism. Why is "der Song" masculine while "das Lied" is neuter? Beats me! Apparently because "song" is simliar to the German "der Gesang" (or the very very old fashioned "der Sang")
There are apparently multiple principles how the gender of a foreign word develops and those are the sites that I found explained it quite understandably:
Wikipedia's article about grammatical gender (http://en.wikipedia.org/wiki/Grammatical_gender#Gender_in_words_borrowed_from_one_language_by_another) has an interesting section about gender of loan words and states a few rules that work in most of the cases... Not only in German but also in other languages.
If the noun is animate, natural gender tends to dictate grammatical gender.
The borrowed word tends to take the gender of the native word it replaces.
If the borrowed word happens to have a suffix that the borrowing language uses as a gender marker, the suffix tends to dictate gender.
If the borrowed word rhymes with one or more native words, the latter tend to dictate gender.
The default assignment is the borrowing language's unmarked gender.
Rarely, the word retains the gender it had in the donor language. This tends to happen more frequently in more formal language such as scientific terms, where some knowledge of the donor language can be expected.
But of course, there are also exceptions and sometimes, words even have multiple genders... Or there are multiple "replaced words" with different genders but only one of them is assumed correct... So, as usual, it's best to memorize the genders as you learn the words.
Since the word for hamburger is masculine, so is a Big Mac. "Ich möchte einen Big Mac, bitte."