Mike Cash: I'm aware that orange is an English word, but I'm not writing 'orange', I'm writing 'orenji'. Orenji may sound similar but it isn't English. So I don't understand, I'm sorry if it's irritating to you that although it "ain't that hard" to figure out, I'm struggling. I figured if you write "Orange" you would write it in Katakana because it's an English word. But Orenji is Japanese, so I don't get why it's written in katakana. Maybe it's just me, I guess.
Hi Alice,
One thing to remember is that English has a lot more sounds than Japanese, and that these sounds can also be used differently.
Let's take ピンク. You might think it doesn't sound like English because of that 'u' sound at the end, but you have to realize that the only final consonant in Japanese (of which I'm aware, and let's ignore things like す having the う component unvoiced, it's a red herring) is 'n.' So there is no way to write, and often Japanese native speakers are unable to say, the final 'k' in 'pink.' Therefore pink turns into pinku or ピンク.
Think of it this way: You have to fit a bunch of round pegs into square holes. You can make small enough round pegs fit through the holes, but you can never make them match perfectly because they will always be round and not square. It's the same. Japanese has a bunch of round sounds and with katakana we try to fit them into the square holes of English words. We can make them fit well enough to get the point across, but they won't match perfectly.
Add to this the confusion of English's inconsistent vowel use, whereby English uses the same symbol (let's say 'i') for a variety of sounds. Japanese uses 'i' or イ for one sound: い So when they write Godiva, which I pronounce ゴダイヴァ, they write ゴヂバ. Godeeba. Does it sound like the English pronunciation? Nope, but the round sounds fit well enough into the square holes that most people (eventually) figure it out. I admittedly constantly get confused by this when I encounter a new one, though as soon as I find out what it is I just file it away in my brain. I've noticed that the more I read and listen the better I get at figuring it out.
The things which really screw with me, though, are katakana like this: タマネギ which means onion, but is in no way I can figure an English loan word. Yet, it is written in katakana.
Side note: I spent over an hour wandering around a station asking shopkeepers where the Godiva chocolate store was because I was supposed to meet someone there. I finally pulled up a picture on my phone and showed it to a clerk after being told over and over by uncounted clerks at stores that they had no idea what I was talking about. Sometimes it just needs to click.
Most people don't share toothbrushes. But I had thought that she had said ヘアブラシ. 
