から details
write + because
kaku kara
because; so — the speaker's own reason
明日テストがあるから、今夜は遊べないよ。
ashita tesuto ga aru kara, kon'ya wa asobenai yo.
I've got a test tomorrow, so I can't hang out tonight. casual
先に帰るね。明日も早いから。
saki ni kaeru ne. ashita mo hayai kara.
I'm heading home first — I've got another early start tomorrow. casual
Examples
because / so — reason clause first, its consequence after
明日テストがあるから、今夜は遊べないよ。
ashita tesuto ga aru kara, kon'ya wa asobenai yo.
I've got a test tomorrow, so I can't hang out tonight. casual
道が混んでいたから、少し遅れました。
michi ga konde ita kara, sukoshi okuremashita.
The roads were crowded, so I was a little late. neutral
時間になりましたから、始めましょう。
jikan ni narimashita kara, hajimemashou.
It's time, so let us begin. neutral
sentence-final から — the reason trails after the point it supports, as assurance or warning
先に帰るね。明日も早いから。
saki ni kaeru ne. ashita mo hayai kara.
I'm heading home first — I've got another early start tomorrow. casual
大丈夫ですよ、コピーは取ってありますから。
daijoubu desu yo, kopii wa totte arimasu kara.
Don't worry — I've kept a copy. neutral
Formation
{V}からattaches to dictionary formplain clause + からattaches to plain clausei-adj + から (高いから)attaches to i-adjectivena-adj + だからattaches to na-adjective{N}だからattaches to noun
Notes
Related patterns
Similar
から asserts the reason as the speaker's own case and comfortably fronts commands, refusals, and opinions; ので presents it as neutral circumstance, so requests and excuses read softer with ので (遅れますので) and pushier with から.
から rests the whole case on one decisive reason; し stacks co-existing reasons and flags the list as open-ended — 安いし近いし offers reasons plural with more implied, 安いから commits to price alone.
Lookalikes
The same から splits on what precedes it — after the て-form it orders events (飲んでから帰る "go home after drinking"), after a finite clause it gives a reason (飲んだから帰る "going home because I drank"); learners routinely misparse one boundary as the other.