Modal Verb 应该 - Obligation/Should

Using 应该 is like adding a polite nudge to your sentence. It is a modal verb. This means it helps another verb express a mood. In this case, the mood is obligation or suggestion. It sits right before the main action. It does not change based on who is talking. You do not need to conjugate it for different people. It stays the same for "I," "you," or "they." It is as steady as a rock. Think of it like a grammar traffic light. It tells the listener which way they should go. It is much softer than a direct command. It leaves a little room for the other person to decide.

1. 1Building a sentence with 应该 is very simple. Just follow these steps:
2. 2Start with the person or thing (Subject).
3. 3Add the word 应该 (yīnggāi).
4. 4Put the action you are talking about (Verb).
5. 5Finish with any extra details (Object).
6. 6For example: 你 (You) + 应该 (should) + 喝 (drink) + 水 (water).
7. 7To make it negative, just add 不 (bù) in front.
8. 8你不应该去 means "You should not go."
9. 9To ask a question, add 吗 (ma) at the end.
10. 10我应该买吗？ means "Should I buy it?"
11. 11You can also use the "A-not-A" style: 应不应该 (yīng bù yīnggāi).

Use 应该 when you want to give advice. Imagine your friend is coughing. You say, "You should see a doctor." In Chinese, that is 你应该看医生. Use it for social duties too. If you are at a dinner, you should say thank you. Use it for logical guesses. If the sky is dark, it should rain soon. 应该下雨了. Use it when you expect something to happen. If you ordered pizza an hour ago, it should be here. 比萨应该到了. It works for job interviews too. You should arrive early for the meeting. It is great for being helpful without being bossy. Even native speakers use it to be polite. It shows you have good manners.

Do not use 应该 for absolute laws. If a sign says "No Smoking," it is not a suggestion. For strict rules, use 必须 (bìxū) instead. Also, do not use it for physical ability. If you want to say you can swim, use 会 (huì). 应该 is about what is right, not what is possible. Do not use it if you are 100% certain of a fact. If the sun is out, do not say it "should" be daytime. Just say it is daytime. 应该 always has a tiny bit of "maybe" in it. It is an opinion or an expectation. Using it for facts sounds a bit weird.

One big mistake is the word order. Some people put 应该 at the end of the sentence. Do not do that. It is not a dessert; it is the main course. It must come before the verb. Another mistake is forgetting the 不 for negatives. Some say 应该不, but it should be 不应该. Also, do not use it with 可以 (kěyǐ) in the same spot. Pick one or the other. Yes, even native speakers mess this up when they are tired. Just remember: Subject + 应该 + Verb. Keep it simple and you will be fine. Think of it like putting on socks before shoes. Order matters!

应该 is "should." 要 (yào) is often "must" or "want." 要 is much stronger and more direct. 必须 (bìxū) is the strongest. It means "absolutely have to." If 必须 is a drill sergeant, 应该 is a helpful librarian. Then there is 想 (xiǎng). 想 is just about what you want to do. 应该 is about what is the right thing to do. Sometimes what you 想 and what you 应该 do are different! For example, I 想 eat cake, but I 应该 eat salad. We have all been there. Choosing the right word changes the whole tone.