1. て (te)
2. で (de)
3. から (kara)
4. ので (node)
5. もので (mono de)
As the connection between two clauses, the て form of adjectives and verbs can indicate a reason at the end of the first clause in a sentence. Note that the て form can also mean “and” (see here). Telling the difference depends on reading the context correctly. English equivalents:‘because,” “since,” “so.”
The roads are crowded, so it’s impossible to get to the airport by 6:00.
Right now the snow is heavy there, so you can’t go (get there) on foot.
2. で (de)
Following nouns, indicates that the noun is the reason for the situation given in the following verb. で can sometimes be made softer in tone by converting it into ので (4) or more direct by replacing it with から (3). English equivalent: “due to”, “owing to”, “because of”…
Because Hayashi-san has been ill, he has been away from the office since last week.
This morning, due to an accident, the train stopped running for a whole hour．
Indicates a reason and can follow a verb, adjective, na-adjective, or noun; nouns and na-adjective must be accompanied by だ when they are used with から. Compared with ので (4) and もので（5)，から is much more direct in giving a cause or reason and is therefore often avoided in polite conversation when the “reason” may somehow offend the other party. English equivalent: “because”.
Hisako: There is a bad cold going around now. Is your boy/girl OK?
Tomomi：Thanks for asking. Our little boy/girl is always full of energy, so he/she should be OK.
Toyama: Want to go golfing this afternoon?
Inaba: Since it’s supposed to rain today, let’s make it tomorrow.
Indicates a reason or cause at the end of a clause, the result of which is given in the following clause. Nouns and na-adjectives take な before ので. のでsounds softer than から (3) and is therefore often used when politeness is called for. When more politeness is required, there is recourse to もので (5). ので is similar to て (1) in that they can both connect clauses, but ので has a softer sound. English equivalents: “because”, “in that”.
During summer vacation this year, there was a bad cold going around, so there was a huge drop in travelers going abroad.
Now, with the economic upturn, the company is apparently doing well.
In that it indicates a cause or reason at the end of a clause and follows verbs, adverbs, and adjectives, もので is similar to, and interchangeable with ので (4); it differs from ので in that it has a more polite sound to it. English equivalents: “because”, “in that”, “for the reason that”.
Yesterday my son/daughter had a fever, so that I wasn’t able to accompany you to the concert. I offer my apologies.
Yamashita: I’m very sorry, but the meeting has taken longer than expected and so I won’t be able to call on you by 6 o’lock.
Nomoto: That’s perfectly all right. I’ll be waiting for you, so don’t concern yourself about it.