专题十 介词和介词短语 ◆介词和介词短语的考查要点介词是虚词,不能单独作句子成分,必须与名词、代词(或相当于名词的其他词类、短语或从句等)构成介词短语,在句中充当一个成分。介词分为:简单介词,如at,in,for等;合成介词,如within,inside,onto,throughout等;短语介词,如according to,out of,because of,by means of,in spite of,instead of等;双重介词,如from behind/above/under,until after等;分词介词,如considering,including,judging (from/by) 等。