too...to是個(gè)常用句型結(jié)構(gòu)，一般表示否定意義。例如:My sister is too young to go to school. 該句型和enough to結(jié)構(gòu)意義相反，例如上句可以改為: My sister is old enough to go to school.

有時(shí)在too...to結(jié)構(gòu)中再加上一個(gè)否定詞，表示肯定意義。可以加在too前，也可以加在to前。例如:

John is never too disappointed to want a try. 約翰決不失望，還想再試一試。

This English gramma book is not too difficult for us to understand.這本語法書并不太難，我們看得懂。

He was too angry not to say it. 他太生氣了，難免要說出這種話來。

She is too careful not to have noticed it. 她那么仔細(xì)，不會(huì)不注意到這一點(diǎn)的。

下面再舉一個(gè)例子，看該怎么翻譯:They seem to be too nervous and were too anxious to leave. 應(yīng)譯為:他們看來過分緊張不安，并且過分急于離開。如果譯為“急于不離開”，顯然是前后矛盾的。說明too...to結(jié)構(gòu)并非只能表示否定意義，也可以表示肯定意思，這取決于too后面的表語形容詞。在be too anxious to do， be too eager to do， be too willing to do， be too easy to do等結(jié)構(gòu)中，均應(yīng)表示肯定意思。例如:

I’m too pleased to meet you. 見到你很高興。

He’s too willing to accept the task. 他樂意接受這項(xiàng)任務(wù)。

so as to有“以便、使得”的意思，用來引導(dǎo)目的狀語，相當(dāng)于in order to，只不過口氣稍弱，并且不能放在句首。例如:

He got up early so as to catch the first bus.

She spoke slowly so as to be heard by everyone.

so as to也可以表示結(jié)果，例如:He struck the snake so as to break its back.他對蛇一擊，結(jié)果打斷了它的背脊。在多數(shù)情況下表示結(jié)果都出現(xiàn)于so...as to的結(jié)構(gòu)中。對比經(jīng)過改動(dòng)后的前面兩個(gè)例句:

He got up so early as to catch the first bus.

She spoke so slowly as to be heard by everyone.