as though和as if沒有什麼區別。as if用得普遍些，卻可引導方式狀語從句和表語
從句，其從句謂語常用虛擬語氣。
(1)引導方式狀語從句
e．g．He closed his eyes as though he were too tired．
他閉著眼睛，好像太累了。
She acted as though nothing had happened．
她裝得好像什麼事也沒發生過似的。
當從句主語和主句主語一致，從句謂語中又含有動詞to be時，可以把主語和to be
一起省去。
e．g．He looked about as though (he was)in search of something．
他四下張望，好像尋找什麼。
He paused as if(he was)expecting Tom to speak．
他停了下來好像期望Tom說些什麼。
He listened as though he was turning to stone．
這孩子一動不動地聽著，彷彿變成了石頭似的。
(2)引導表語從句
e．g．It looks as if it"s going to rain．
看樣子天要下雨了。
It seems as if I"m the first one here．
看起來我是第一個到這裡的。
as though和as if從句用虛擬語氣，還是用陳述語氣。完全根據具體情況而定。如果
從句表示的意思與事實完全相反，或者純粹是一種假設，通常用虛擬語氣。
e．g．When
a pencil is partly in a glass of water．it looks as if it were broken．
當鉛筆一部分放進水裡，看起來好像折斷了似的。(虛擬)
You look as if you are friends．
你們看起來像朋友似的。
as though和as if沒有什麼區別。as if用得普遍些，卻可引導方式狀語從句和表語
從句，其從句謂語常用虛擬語氣。
(1)引導方式狀語從句
e．g．He closed his eyes as though he were too tired．
他閉著眼睛，好像太累了。
She acted as though nothing had happened．
她裝得好像什麼事也沒發生過似的。
當從句主語和主句主語一致，從句謂語中又含有動詞to be時，可以把主語和to be
一起省去。
e．g．He looked about as though (he was)in search of something．
他四下張望，好像尋找什麼。
He paused as if(he was)expecting Tom to speak．
他停了下來好像期望Tom說些什麼。
He listened as though he was turning to stone．
這孩子一動不動地聽著，彷彿變成了石頭似的。
(2)引導表語從句
e．g．It looks as if it"s going to rain．
看樣子天要下雨了。
It seems as if I"m the first one here．
看起來我是第一個到這裡的。
as though和as if從句用虛擬語氣，還是用陳述語氣。完全根據具體情況而定。如果
從句表示的意思與事實完全相反，或者純粹是一種假設，通常用虛擬語氣。
e．g．When
a pencil is partly in a glass of water．it looks as if it were broken．
當鉛筆一部分放進水裡，看起來好像折斷了似的。(虛擬)
You look as if you are friends．
你們看起來像朋友似的。