と, ば, たら, なら — which Japanese “if” do you use?
Japanese has four ways to say “if / when,” and they are not interchangeable. Here they are side by side — what each one is for, and the specific distinctions between every pair.
At a glance
The difference between each pair
Both express general cause-effect, but と stresses an inevitable, every-time result (押すと開く); ば frames a more hypothetical condition (安ければ買う).
と demands an automatic/repeating result and bans commands in the main clause; たら is the flexible everyday 'if/when' that freely allows requests and intentions.
と reports an objective automatic result; なら responds to something just raised ('if that's the case…') and never expresses an automatic outcome.
ば leans general/hypothetical and prefers state conditions; たら is concrete and sequential and freely allows requests. When in doubt in speech, たら is the safer default.
ば states a plain hypothetical; なら picks up a premise just raised ('if that's so') and can place its clause after the result in time.
See these in real sentences
Rules blur; examples stick. Jengo shows each of these patterns inside real Japanese sentences so the difference becomes intuition.