下面舉例說明il-，im-和ir-的構詞特點。 

illegal [ il- (in-) = not 不；legal a. 合法的→]a. not lawful 不合法的，非法的 / Driving faster than the speed limit is illegal. 超速行車是違法的。

illegality n .非法；違規(guī) 

illegalize v. 使非法；宣布為非為

imbalance [ im- (in- ) = lack of 不；balance n. 平衡→]n. lack of balance 不平衡 / The trade imbalance in the country has lessened. 該國的貿易不平衡已經減少。

immortal [ im- (in-) = not 不；mortal a. 終有一死的→]a. not mortal; living forever 不朽的；永存的 / The fame of Shakespeare should be immortal. 莎士比亞的聲譽永存。

immortality n. 不朽，永存；不滅的聲望 

immortalize v. 使不朽，使不滅

imprudent [ im- (in-) = not 不；prudent a. 謹慎的→]a. not prudent; heedless 輕率的；魯莽的 / It is imprudent to run into something without thinking what may happen. 不考慮可能發(fā)生的結果而匆忙行事是很輕率的。

imprudence n. 輕率，魯莽

irregular [ ir- (in-) = not 不；regular a. 不規(guī)則的→]a. not regular; not according to rule 不規(guī)則的，無規(guī)律的 / He is irregular in his attendance at school. 他不時曠課。

irregularity n. 不規(guī)則，無規(guī)律