で has many uses. It can be used for sentences like:
I went to the park by bus. バスで公園に行きました。
Or 'with' when talking about objects such as:
パソコンで日本語とイタリア語を勉強しています。- With my PC, I'm studying Japanese and Italian.
It can be used with 'jibun' (myself) and hitori (alone)
一人でこのケーキを作りました。-I made this cake alone.
自分で料理しました。- I cooked by myself.
It can be used as a price for something:
曙ﾜドルでゲームを買いました。- I bought this game at the price for 15 dollars.
A location where something took place:
喫茶店でドーナツを食べました。- I ate a doughnut at the cafe.
It can mean 'within'...
一日で本を読みました。- I read it within a day.
As with である, I do not see why this has it's own page. で is the "て-form" of だ and as such operates largely the same way any て-form would. For example: そのペンを使って書いた。- "I wrote it using that pen". The fragment "using that pen" is equivalent to the fragment "by car" in the example given by the author. This simply means that when だ's て-form is used (で) with a noun, we add "by", whereas in the case of a different verb's て-form, that verb + ing suffices in expressing the means by which something is done. When critically analyzing the fundamental grammatical structure of this Japanese without applying our English-based perceptions to it, で should not be distinguished from だ on a separate page. It's colloquial interpretations according to English-based perceptions might just be sidenotes on that page.
I think that convoluted explanation proves why "de" needs its own separate page. While the explanation may be correct, it's too labyrinthine to be usefully instructive when "de" pops up in Japanese study (quite early). "De" functions as a particle, regardless of its roots, and it's too comon a term to be stuck as a footnote to "da". It deserves its own page.
Eeker, why don't you make a new entry?
I find it most helpful to have the convoluted explanation and the technically redundant but simpler entry in the same place. Thanks Amatuka and Eeker.
This might be a result of applying the English-based (or foreign-based in general) perceptions, but most of the people reading this are actually English speakers trying to learn Japanese and articles like this one make the learning easier, especially in the early stage, when you don't necesarily know about て-forms.
Eeker, thanks for the explanation. Suddenly です as 「-で あります」starts to make much more sense.
Sometimes a で is just a で......... if you bring up that first explanation to an average japanese person, they`d probably look at you like you were nuts!!!!
I agree with dezil and 9000--lights and bells went off after I read Eeker's entry. That said, I'm rarely a purist, and I think a separate entry is merited for the JLPT 2/3 levels (including at least a pointer to Eeker's entry). Thanks everyone for your contributions.
I put many usages of the word de up on my site where I teach Japanese www.freewebs.com/kanjiwebs/ as this is not near enough of examples for people to know what de is. At least 1 example for each usage and that is not near as what is shown here.
While I appreciate, though seldom understand, the nuances of language, as a beginner in the learning of Japanese, I really appreciate keeping things as simple as possible, such as giving ”で”it's own entry. Also, I am grateful for the use of hirigana in addition to kanji.