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．