had better(常簡略為"d better)是一固定片語，had better"最好"，用於表示對別人的勸告、建議或表示一種願望。其用法有以下幾點：
一、had better後面必須跟動詞原形。
had better後跟動詞原形(即不帶to的不定式)，構成had better do sth.句型。
這裡的had不能用have來替換。如：
You"d better go to hospital at once.你最好立即去醫院看病。
Tom, you"d better go there today.湯姆，你最好今天去那兒。
二、主語不論是第幾人稱，句子不論是什麼時態，都要用had better的形式。如：
Now you(he，we) had better listen to the teacher.你(他，我們)現在最好聽老師講。
三、had better可用於的時態。
1.had better用於指現在。如：
Now you had better listen to the radio.你現在最好聽收音機。
You had better be quiet.你最好安靜一些。
2.had better用於指將來。如：
You had better start tomorrow.你最好明天動身。
We had better buy the more expensive one. It will last much longer and so it will be cheaper in the end.我們最好還是買貴些的,它更經久耐用，所以到頭來，它還是更便宜些。
3.had better用於進行式，表示講話人提出建議時，動作正在進行。如：
We had better be watching the TV play.我們最好現在就看到電視劇。
We had better be starting back now.我們最好現在就動身回去。
4.had better + have + V-ed可表示"本該做而沒有做的事"。如：
You had better have done it .如果你把那件事辦妥就好了。(但實際上你沒有那樣做)
You had better have stayed with us .要是當時你和我們呆在一起多好啊。(實際上沒有)
四、had better的否定式。如：
常用的否定形式是將否定副詞not直接放在had better的後面。如：
You had better not miss the last bus.你最好不要錯過末班公共汽車。
You had better not leave for Nanjing the day after tomorrow.你最好後天不要動身去南京。
注意：否定副詞not絕不能放在had的後面。如：不能說：You hadn"t better go.而應該說：You had better not go.
五、had better的疑問式。
had better通常不以普通疑問句的形式出現。但有時用於否定疑問句，常用Hadn"t+主語+better...?結構,作為一種勸告形式，比肯定形式的語氣更婉轉一些。如：
Hadn"t you better take an umbrella?你不認為該帶一把傘嗎?
Hadn"t you better ask him first?你不認為該先問問他嗎?
六、had better在反意疑問句中。
在反意疑問句中，疑問部分一般用"had+主語？"，但有時可用"will you?"表示一種請求或建議。如：
You"d better not go out today, had you? 今天你最好不要外出，好嗎？
I must stay at home this afternoon. You had better come to my house, will you?今天下午我必須留在家裡，你最好來我家，好嗎？
七、在祈使句中，had有時可以省略。如：
Better not do it .最好別做那事。
Better not wait for them.最好不要等他們。
八、had better的被動式。
You had better do it.->It had better be done.
You had better have done it.->It had better have been done.
九、had better在間接引語中的用法。
在直接引語變為間接引語的過程中，had better同第一人稱或第三人稱連用時，保持不變；had better同第二人稱連用時，可以保持不變，也可用advise+賓語+不定式(賓補)來表示。如：
He said, "Ann had better hurry."->He said (that) Ann had better hurry.
He said, " I had better hurry."->He said (that) he had better hurry.
He said to me," You had better hurry." ->He said (that) I had better hurry.->He advised me to hurry.
十、had better在表示對別人勸告、建議時，不宜用於與陌生人、長輩及上級的交談中。
對長輩說話時，最好不用had better。比較有禮貌的說法是：It might be better for you...；
It would be better for you...。如：
It might be better for you to help me，Grandpa.爺爺，您最好能幫我一下。
had better(常簡略為"d better)是一固定片語，had better"最好"，用於表示對別人的勸告、建議或表示一種願望。其用法有以下幾點：
一、had better後面必須跟動詞原形。
had better後跟動詞原形(即不帶to的不定式)，構成had better do sth.句型。
這裡的had不能用have來替換。如：
You"d better go to hospital at once.你最好立即去醫院看病。
Tom, you"d better go there today.湯姆，你最好今天去那兒。
二、主語不論是第幾人稱，句子不論是什麼時態，都要用had better的形式。如：
Now you(he，we) had better listen to the teacher.你(他，我們)現在最好聽老師講。
三、had better可用於的時態。
1.had better用於指現在。如：
Now you had better listen to the radio.你現在最好聽收音機。
You had better be quiet.你最好安靜一些。
2.had better用於指將來。如：
You had better start tomorrow.你最好明天動身。
We had better buy the more expensive one. It will last much longer and so it will be cheaper in the end.我們最好還是買貴些的,它更經久耐用，所以到頭來，它還是更便宜些。
3.had better用於進行式，表示講話人提出建議時，動作正在進行。如：
We had better be watching the TV play.我們最好現在就看到電視劇。
We had better be starting back now.我們最好現在就動身回去。
4.had better + have + V-ed可表示"本該做而沒有做的事"。如：
You had better have done it .如果你把那件事辦妥就好了。(但實際上你沒有那樣做)
You had better have stayed with us .要是當時你和我們呆在一起多好啊。(實際上沒有)
四、had better的否定式。如：
常用的否定形式是將否定副詞not直接放在had better的後面。如：
You had better not miss the last bus.你最好不要錯過末班公共汽車。
You had better not leave for Nanjing the day after tomorrow.你最好後天不要動身去南京。
注意：否定副詞not絕不能放在had的後面。如：不能說：You hadn"t better go.而應該說：You had better not go.
五、had better的疑問式。
had better通常不以普通疑問句的形式出現。但有時用於否定疑問句，常用Hadn"t+主語+better...?結構,作為一種勸告形式，比肯定形式的語氣更婉轉一些。如：
Hadn"t you better take an umbrella?你不認為該帶一把傘嗎?
Hadn"t you better ask him first?你不認為該先問問他嗎?
六、had better在反意疑問句中。
在反意疑問句中，疑問部分一般用"had+主語？"，但有時可用"will you?"表示一種請求或建議。如：
You"d better not go out today, had you? 今天你最好不要外出，好嗎？
I must stay at home this afternoon. You had better come to my house, will you?今天下午我必須留在家裡，你最好來我家，好嗎？
七、在祈使句中，had有時可以省略。如：
Better not do it .最好別做那事。
Better not wait for them.最好不要等他們。
八、had better的被動式。
You had better do it.->It had better be done.
You had better have done it.->It had better have been done.
九、had better在間接引語中的用法。
在直接引語變為間接引語的過程中，had better同第一人稱或第三人稱連用時，保持不變；had better同第二人稱連用時，可以保持不變，也可用advise+賓語+不定式(賓補)來表示。如：
He said, "Ann had better hurry."->He said (that) Ann had better hurry.
He said, " I had better hurry."->He said (that) he had better hurry.
He said to me," You had better hurry." ->He said (that) I had better hurry.->He advised me to hurry.
十、had better在表示對別人勸告、建議時，不宜用於與陌生人、長輩及上級的交談中。
對長輩說話時，最好不用had better。比較有禮貌的說法是：It might be better for you...；
It would be better for you...。如：
It might be better for you to help me，Grandpa.爺爺，您最好能幫我一下。