得【děi】

得děi before a verb says you have to do something. It is spoken and casual; in writing and formal speech the same idea is 必须.

The same character is read de when it follows a verb, as in 跑得快. 得děi always comes before the verb.

"It takes"

Before a length of time or an amount of money, 得děi says what something will take or cost.

The negative is 不用

得děi doesn't take 不. "Don't have to" is 不用.

• × 我不得去 → 我不用去

得 or 应该

应该 is advice, and the listener could ignore it. 得děi leaves no choice.