| business | package | truthfulness | unsuccessful |
| useless | anteroom | workmanlike | agreement |
| prefix | monotone | nervousness | uniformity |
| beautify | breakage | disrespectful | misguidance |
| semicircle | pleasant | perfection | crystallize |
| kingship | sameness | progressive | precaution |
| incase | subway | undeniable | imaginary |
| enrich | disown | displeasure | supernatural |
| pianist | readmit | endurance | melodious |
| bicycle | adjuster | reaction | interlineal |
Exercise 53
When the prefixes ad, con, and in are used to form English words, the final consonant of each is often changed to the initial consonant of the root to which it is joined.
Ad assumes the forms ab, ac, af, ag, al, an, ap, ar, as, at, assimilating the d with the first letter of the word to which it is prefixed; as,
| ab-breviate | al-literation | ar-rest |
| ac-cept | al-lot | as-sign |
| ac-cumulate | an-nex | as-sist |
| af-fect | an-nounce | at-tract |
| af-flict | ap-position | at-tribute |
| ag-gregate | ap-prove | at-tune |
Con assumes the forms col, cor, com, by assimilation; it takes the form com before p; and it drops the n before a vowel; as,
| col-lateral | com-mercial | com-pose |
| col-lect | cor-relate | co-operate |
| com-mission | cor-respond | co-ordinate |
In assumes the forms il, im, ir, by assimilation and takes the form of im before p.
| il-lusion | im-migrate | ir-ruption | im-port |