Best answer
牛 うし ushi
Next time use
Japanese Dictionary please.
Answer
There are a number of ways to say “because” in Japanese, and even though some of the other answers might make it seem that way, they are not necessarily interchangeable.
～せいで or ～のせいで:
～せいで (~sei de) is used to ascribe blame. It’s only used with negative outcomes, and indicates that the actor mentioned in the first clause is at fault. ジョンさんが遅れてしまったせいで、私たちは電車に間に合わなかった。(“We didn’t make the train because Jon was late.”) When following a noun, のせいで is used.
～おかげで or ～のおかげで:
Conversely, if the outcome is positive, ～おかげで (~okage de) is used to give credit. One common function is to humble yourself using it when speaking to or about superiors. When asked “お元気ですか？” (“Are you well?” or “How are you?”) by someone you’re not necessarily close to, a common (and elegant) response is “はい、おかげさまで” (“Yes, thanks to you.”). Sometimes it will be written with its kanji as お蔭で, but usually it is just written in hiragana.
～で:
～で (~de) is similar to both of the above, but does not give any judgement. It simply reports information. 雨で試合は中止になった。(“The game was cancelled because of the rain.”)
～ため, ～ためで:
～ためで (tame de) is similar to ～で in that it reports information, however it is usually used if the effect is something that was decided on due to the cause (cf. ～ために “~tame ni” – “for” or “for the sake of”). 吹雪のためで、新幹線は今停車している。(“Due to the blizzard, the Shinkansen is currently halted.”)
～から・～ので:
The first “because” most people learn in Japanese is ～から (~kara). It is the most straightforward way of saying because, and is the one used in most situations. Similar to ～から is ～ので (~node), which is generally seen as a softer, more indirect form of ～から. In most cases, they are interchangeable, however, if you are asking for something from someone, you want to avoid ～から. It’s directness is likely to put someone off, especially if you’re asking for a favor.
“I have a fever, so can I go home early today?”
熱が出ているから帰らせていただけませんか？is a little too direct.
熱が出ているので帰らせていただけませんか？sounds softer, and is less likely to offend someone.
Of course, the difference between ～から and ～ので is one of the most hotly debated topics in Japanese linguistics, so you are as likely to find someone who says they are always interchangeable. In matters of 上下関係, however, it is usually better to err on the side of caution.
Often, if the result is negative, it will be left implied and the sentence will trail off after ～ので or ～から
電車が来なかったので、、（遅くなってしまった）”The train didn’t come so… (I was late)”
There are other ways to say because, also. You can begin a sentence with なぜなら (naze nara) or なぜならば (naze naraba), which is used to add emphasis to a reason. When giving an explanation, you can end the sentence with ～んだ (~nda) or ～だからだ (~dakarada). There are other ways, too, that I am just too lazy to include in this answer.
Japanese is a rich, nuanced, fascinating language.