英文的問題 急急急!! 星期一就要考了

Imperative in grammar is a verb form (mood) that expresses a command.In "Come here!" the verb come is an imperative or in the imperative mood.It's something that must be done.
Compare :-Indicative ; subjunctive.Indicative is a verb form that describes an action or states a fact in"He comes here often---comes" or "She passed the test-----passed."
(1)Students, (close) your books now.
(2)Let's (play) baseball together now.
(1) and (2) are Imperative mood ,they are something that must be done.
Participle in Grammar is a non-finite verb form that can be used in compound forms of the verb or as an adjective. English has 2 participles, the past participle and the Present Participle.
(1) Closing the books, students are seen doing actions on adjective participles.
(2)Playing baseball together now, we are" touch and run" players.

兩句都不用。 第1句中的close只是用作祈使的用途，不用加ing，now只是強調句子的語氣，增強說服力。第2句的play前有let，let是madal verb(情態動詞)，在這種動詞後的動詞不用作出任何改變，所以play不用加ing。這兩句其實都是祈使句，因為兩句都是叫對方做某些事情。通常祈使句的開頭第1個英文字是動詞。

1.Students，(close) your books now.
--這是命令和說話,所以不用加ing.但如果不是說話,大多都要加ing,
例如:he is reading book now.

2.Let's(play)baseball together now.
--Let's後面的verb多數不轉tense

1.Students，( close ) your books now.
2.Let's(play )baseball together now.
請問這兩句的動詞要加ing嗎??
Ans. No, 不可加 ing
Close your books(now). 是command 命令式 /祈使句, 不要被 now 誤導!
e.g Children, get to work now,
Let's + 動詞原形, 是一種提議 suggestion, , 不要理 now!
e.g Let's eat our lunch now.

不用加ing,因為我們通常有am,is ,are才加ing,你那句是命令:
close your book now ,沒人說students,closing your book now 除非那句是描述同學正要收好那書,如果是這樣,就改寫成:The students are closing their books now,那人稱要轉,所以不加ing is correct!同樣道理,第二句是邀請句,沒人說let's playing baseball together now !in my opinion,you shouldn't use ing!