Conjunction 既然...就

This grammar pattern works in two distinct parts. First, we have the 既然 part. This part introduces a fact that both people usually know. It is not a surprise. It is the "given" information. For example, "Since you are here..." or "Since it is expensive..." Second, we have the 就 part. This is the result, the suggestion, or the logical next step. It answers the question: "So what?" If you are here, 就 let's have coffee. If it's expensive, 就 don't buy it. The word 既然 usually starts the sentence. However, the subject can sometimes jump in front of it. The word 就 always stays in the second half. It acts like a bridge leading to the action. It’s important to remember that 就 is the glue here. Without it, the sentence feels like it’s missing a limb. Even if you don't translate 就 as "then" in English, it must be there in Chinese. It signals that the second part is a direct consequence of the first. It’s a very satisfying structure to use because it feels very complete.

1. 1Using this pattern is like following a simple three-step recipe.
2. 2Start with 既然 and state the known fact. This can be a situation, a condition, or a person's state. Example: 既然 you are tired.
3. 3Add a comma to catch your breath.
4. 4Use 就 before the verb or suggestion in the second clause. Example: 就 go sleep.
5. 5The basic formula looks like this: 既然 + Fact, (Subject) + 就 + Action/Result.
6. 6Where does the subject go? You have some flexibility! You can say 既然你... (Since you...) or 你既然... (You, since...). Both are perfectly fine and mean the same thing. Usually, putting the subject first feels a bit more informal and punchy. Putting 既然 first feels a bit more explanatory. If the subject is the same for both halves, you can often drop it in the second half. For example: 既然饿了，就吃吧 (Since [you're] hungry, then eat). It's efficient, just like a quick text message to a friend. If the subjects are different, just make sure they are clearly placed. For example: 既然下雨了，我们就不去了 (Since it rained, we then aren't going). Note how 我们 comes before 就. This is a strict rule: 就 always wants to be right next to the action or the result it's triggering.

Use this when the "reason" part is an established fact. You aren't speculating about the future. You are dealing with the present or a settled past.

• Ordering Food: You and your friend are at a famous spicy noodle shop. 既然 we are here, 就 we must try the level 5 spice! (Good luck to your stomach!)
• Social Plans: Your friend is already at your house. 既然 you are already here, 就 stay for dinner.
• Work/Study: You finished your homework early. 既然 I finished, 就 I will play video games.
• Giving Advice: Your friend keeps complaining about their old phone. 既然 you don't like it, 就 buy a new one.

It is perfect for making suggestions that feel "obvious." It’s a very persuasive way to speak. When you use 既然, you are saying, "Look, we both see this fact, so my suggestion makes perfect sense, right?" It’s great for negotiating or just being a helpful friend. You’ll hear it in movies when a character finally gives in to a plan. "Since we've come this far, then let's finish it!"

Don't use this for "if" scenarios. If there is a chance the condition might not happen, use 如果 (rúguǒ) instead. For example, if you say "If it rains tomorrow, I'll stay home," use 如果. You don't know if it will rain yet. If it is *currently* raining outside your window, use 既然.

Also, avoid using it for simple cause-and-effect that lacks a logical "next step" or "decision." If you just want to say "I am late because there was traffic," use 因为...所以. 既然 is much more about the *reaction* to a situation rather than just explaining the cause of it. It’s about the forward motion. If you use it just to explain a boring fact without a suggestion or a new decision, it sounds a bit dramatic and strange. Like saying, "Since 1+1=2, then it is 2." That’s just being a math robot, not a conversationalist!

• Forgetting the 就: This is the most common mistake. Beginners often say 既然太贵，我不买. It sounds choppy and incomplete. You need that 就 to link the logic. Always remember: 既然 and 就 are best friends. Don't separate them.
• Mixing with 因为: Don't say 因为...就. 因为 likes to hang out with 所以. 既然 likes to hang out with 就. Mixing them is like wearing a tuxedo with flip-flops. It just doesn't match.
• Wrong placement of 就: Never put 就 before the subject. It’s 我就..., not 就我.... Think of 就 as a magnet that is pulled toward the verb. It wants to be as close to the action as possible.
• Using it for guesses: Don't use 既然 if you are unsure. If you aren't 100% sure your friend is hungry, don't say "Since you are hungry..." It might sound a bit pushy. Use "If" instead.

Let’s look at 因为...所以 (yīnwèi... suǒyǐ) vs. 既然...就.

因为...所以 is for objective explanation. "Because I was sick, I didn't go." It focuses on the reason.

既然...就 is for subjective decision-making. "Since I am sick, I will rest." It focuses on what we should do now that we know the fact.

Think of 因为 as looking backward at the past to explain things. Think of 既然 as looking at the present to decide the future.

Another one is 如果...就 (rúguǒ... jiù).

如果 is for a 50/50 chance. "If you come..." (Maybe you will, maybe you won't).

既然 is for a 100% reality. "Since you are here..." (You are standing right in front of me).