請英文高手教教我，使役動詞與祈使句的差別?

祈使句是動詞的語氣（mood）變化之一。
(You) Get out of my room! 是下達命令，屬於祈使語氣。這句裡的get屬於不及物動詞，不當作使役動詞用。

三種語氣分別是：
直說語氣：Indicative Mood: He is kind.（他和善）
祈使語氣：Imperative Mood: Be kind. （要和善）
假設語氣：Subjunctive Mood: If you were kind, they would like you.（假如你對人和善，他們定會喜歡你）

使役動詞(causative verbs)顧名思意即在造成另一件事發生。

get在當使役動詞用時，是及物動詞：
I'll get him to do it. （get + 受詞＋不定詞）受詞為人，指使這人去做某件事。
I must get my hair cut.（get +受詞＋過去分詞）受詞為事物，使這件事被別人做。
上述的「不定詞」和「過去分詞」是「受詞補語」。

有些使役動詞的受詞補語，必需使用無to的不定詞（即bare infinitive），如：
John makes me laugh.（使役動詞用在直說語氣）
He made us work hard. (＝We were made to work hard by him.被動是要用有to的不定詞）

Let me hear from you.（使役動詞用在祈使語氣）
Let it be.
Let him say what he likes.
He let her see what she had done.（使役動詞用在直說語氣）

(A) Causative=cause USAGE:-When compare cause(=have,give)make,and let:-
Cause with an object can be formal:-eg:-Cigarettes may cause cancer disease.Why do Leung always cause trouble ?TW earthquake caused several roads to collapse.---Make never use "to":-eg:-It's a sad movie that makes you cry.---Let(=allow)The valve lets water enter the pump in the kitchen. Let me hear from Leung on the cause again:-Cause:-eg:-What caused the accident? The children have been charged with a causing on criminal damage ! His illness caused him death !!!This TW car caused me troubles !!!Her irresponsible behaviour has caused anxiety for her whole family.They believed inflation is caused by cy.Leung.=Leung-don't complain without good cause, good reasons !!!

(B)IMPERATIVE mood:-in grammar expresses a command in "Come Here !" something must be done.--Job creation has become an Imperative for the government--a moral imperative.Prompt action is Imperative It's Imperative that Leung (should) tell Government immediately showing proud.---Get out of my house+Leave me alone+Be Kind is an Imperative manner..Hence try compare Declarative, Interrogative is better than compare Indicative,Subjunctive.

1..使役動詞make,let,have,give等，是導致其他事件發生。例如I have my hair cut.
2.祈使句是直接命令，若語氣強烈結尾用驚嘆號。例如Get out of my house! 而語氣較弱表達時用句號，例如Leave me alone.讓我冷靜一下
3.一般使役動詞後接動詞用原形。表示動作同時發生，If possible.please be free to let me know. 這句是祈使句內含使役動詞