だからso; that's why
だから starts a new sentence with "so" or "that's why". The reason is the sentence before it. It is the everyday word in conversation.
so
I have an early morning tomorrow, so I'm going to bed now.
that's why
The trains have stopped. That's why the station is so crowded.
How to form it
Reason。 だから、+ what follows
It comes first in the new sentence, usually with a comma after it. The polite form is ですから.
So
What follows だから can be a decision, a suggestion, a request, or simply the result.
It's cold outside, so let's wear coats.
It's already late at night, so let's continue tomorrow.
This shop is closed on Mondays. That's why it isn't open today.
This road is under construction, so please take another route to the station.
"So", not "because"
What comes after だから is the result; the reason came before it. English speakers reach for it to say "because", and the sentence comes out backwards. "Because" is から, at the end of the reason.
Not said: 今日は
(I'm not going out today. Because it's raining.)
Say 雨が降っているから、今日は出かけない.
Inside one sentence, after a noun or a な-adjective, だから is that から with だ in front of it.
The shop is closed today, so let's come back tomorrow.
Two sentences. だから starts the second: "so".
The shop is closed today, so let's come back tomorrow.
One sentence. だ and から close the reason: "because".
だから…んだ: so that's why
You find out the reason for something you had noticed. だから with んだ or んですね at the end is "so that's why".
Tanaka lived in America for ten years, you know.
So that's why he is good at English.
Starting a reply: "like I said"
When someone asks again about something you have already explained, a reply that opens with だから means "as I told you". It sounds impatient, and ですから is no gentler. A plain answer to どうして ends in から.
You're really not coming? Why?
Like I said, I have a test tomorrow.
B has already explained once. The first time it was 明日テストがあるから.
なので: a softer "so"
In conversation many people also start a sentence with なので. It is a softer "so", and unlike だから it is as common in polite talk as in casual. It is only this plain "so": it does not open "so that's why" or "like I said". It stays out of careful writing; in a report or an essay the word is そのため.
I have work from the morning tomorrow. So I'm going home early today.
Close neighbours
それでN4
Also "so", for telling what happened next. "So let's…" and "so please…" follow だから, not それで.
I suddenly came down with a fever, so I missed my afternoon classes.
そのためN3
"Because of that". For reports and news, where だから sounds too chatty.
Strong winds have continued since last night. Because of that, the boats cannot return to port.
Check yourself
1Which one makes sense?
Choose an answer to see why.
2What is B saying?
A
Choose an answer to see why.
3You ask a friend a second time why they won't lend you their bike, and the reply opens with だから. How does it sound?
Choose an answer to see why.
More sentences
He practices every day. That's why he is good at it.
The rain is getting heavier, so let's go home early today.
We are leaving early tomorrow, so let's get our luggage ready tonight.