既然…就…grammar point · tier 1 · 既然…就… (since … then, given that)
Draws a conclusion from a premise already taken as true: given that A holds, then B follows.
字源 FORM what the parts do
既 sets the premise down as already so: a food bowl (皀) beside 旡, a person turned from it, full — the meal done. 然 was the word for burning, borrowed into grammar for 'so, thus' (燃 took the burning back). 就 climbs straight to the high hall (京 + 尤) — the next step taken at once. Together: given that A is already so, B follows.
故事 STORY a scene to remember it by
The bowl is already empty, the eater turned away; so the table gets cleared at once.
自撰字源記憶法
框 · Frame
既然 [established premise]，就 [conclusion that follows]
觸 · Trigger
You take a fact as already settled between you and the listener and draw the conclusion it forces.
序 · The move
1State the settled premise after 既然.Is this already true and shared, not a hypothesis? A case that may be false wants 如果/要是, not 既然.
2Open the conclusion clause with 就 before its verb.Does 就 sit right before the verb, after the subject if there is one?
3Confirm the conclusion is drawn from the premise, not merely caused by it.Reads as 'given that A, then naturally B', not a bare report 'because A, B happened'. A finished past event wants 因為…所以….
例 · Examples
1既然since, given that在學校at school上課take classes，就then可以may, can利用make use of時間time好好well, properly使用use學校的資源resources。
Since you're already taking classes at school, you may as well make good use of your time and the school's resources.
因為…所以… reports an actual cause and its result. 既然…就… draws a conclusion (often a suggestion or decision) the listener is steered toward, from a premise both already grant.
雖然…可是…
雖然 grants A then turns against it; 既然 grants A then runs with it to the conclusion A supports.
既然就下雨，我不去。 ✗ → 既然下雨，我就不去。 ✓ (就 belongs in the conclusion, not after 既然)
如果你已經到了，就進來吧。 ✗ → 既然你已經到了，就進來吧。 ✓ (premise already true takes 既然, not the hypothetical 如果)
English 'since' covers both time and reason, so learners reach for it where the premise is hypothetical; 既然 only works on a premise already taken as true. English also drops 'then', so learners drop 就, but the conclusion clause keeps it.