在英語的合成詞（compound words）中，合成動詞（compound verbs）的數(shù)目較少，主要有下面三種類別：
㈠副詞+動詞，如 outdo, overcome, undermine, upset, cross-question, withhold, backbite 等。
㈡名詞+動詞，如 sunbathe, sidetrack, typewrite, house-hunt, browbeat, hoodwink, waylay 等。
㈢形容詞+動詞，如 whitewash, safeguard, shortlist, blackmail 等。
這三類合成動詞中，以第一種最為豐富，特別是那些由“over, under, out”引導的，更顯得多彩多姿。
由 over 引導的合成動詞含有“太多、過多”的意思，如： overact, overburden, overcharge, overdo, overdress, overeat, overestimate, overpower, overpraise, overproduce, overprotect, overrule, oversleep, overspend, overstate, overstay, overwork 等。
由 under 引導的合成動詞含 有“太少、不足”的意思，如： undercharge, underpay, underrate, understate, undervalue, underwork 等。
由 out 引導的合成動詞則含有“超過、勝過”之意，如： outdo, outgrow, outlive, outnumber, outside, outrank, outshine, outstay, outstrip, outweigh, outwit 等。
現(xiàn)在舉些句子示范：
① The food cost $3, but he was overcharged by 50 cents.
② Some romantic scenes in our TV shows were overdone.
③ Don't overstate your predicament or people will not believe you.
④ Some reporters understated the seriousness of the regional financial turmoil.
⑤ The staff of the company felt that their contribution had been undervalued.
⑥ Chinese swimmers outdid their opponents.
⑦ This type of computer has outlived its usefulness.
⑧ The advantages of the new salary scheme far outweigh its disadvantages.
最后，必須注意的是：不是凡是“over ”就是“過多、太多” ，凡是“under”就是“太少、不足”或凡是“out”就是“超過、勝過”。反之，有些合成動詞根本和這幾個副詞的意思風馬牛不相及。例如：
● overhear（無意中聽到）
● overlook（俯視、疏忽、忽略）
● oversee（監(jiān)督）
● overshadow（使……暗然失色）
● overthrow（*）
● overturn（使翻覆）
● undergo（經(jīng)歷、遭受）
● underline（在……劃線、強調(diào)）
● undermine（破壞）
● underpin（加強、鞏固）
● understand（理解）
● understudy（充當替手）
● undertake（擔任、著手）
● outline（略述）
● outrage（虐待，侵害）
● outspread（伸展）
㈠副詞+動詞，如 outdo, overcome, undermine, upset, cross-question, withhold, backbite 等。
㈡名詞+動詞，如 sunbathe, sidetrack, typewrite, house-hunt, browbeat, hoodwink, waylay 等。
㈢形容詞+動詞，如 whitewash, safeguard, shortlist, blackmail 等。
這三類合成動詞中，以第一種最為豐富，特別是那些由“over, under, out”引導的，更顯得多彩多姿。
由 over 引導的合成動詞含有“太多、過多”的意思，如： overact, overburden, overcharge, overdo, overdress, overeat, overestimate, overpower, overpraise, overproduce, overprotect, overrule, oversleep, overspend, overstate, overstay, overwork 等。
由 under 引導的合成動詞含 有“太少、不足”的意思，如： undercharge, underpay, underrate, understate, undervalue, underwork 等。
由 out 引導的合成動詞則含有“超過、勝過”之意，如： outdo, outgrow, outlive, outnumber, outside, outrank, outshine, outstay, outstrip, outweigh, outwit 等。
現(xiàn)在舉些句子示范：
① The food cost $3, but he was overcharged by 50 cents.
② Some romantic scenes in our TV shows were overdone.
③ Don't overstate your predicament or people will not believe you.
④ Some reporters understated the seriousness of the regional financial turmoil.
⑤ The staff of the company felt that their contribution had been undervalued.
⑥ Chinese swimmers outdid their opponents.
⑦ This type of computer has outlived its usefulness.
⑧ The advantages of the new salary scheme far outweigh its disadvantages.
最后，必須注意的是：不是凡是“over ”就是“過多、太多” ，凡是“under”就是“太少、不足”或凡是“out”就是“超過、勝過”。反之，有些合成動詞根本和這幾個副詞的意思風馬牛不相及。例如：
● overhear（無意中聽到）
● overlook（俯視、疏忽、忽略）
● oversee（監(jiān)督）
● overshadow（使……暗然失色）
● overthrow（*）
● overturn（使翻覆）
● undergo（經(jīng)歷、遭受）
● underline（在……劃線、強調(diào)）
● undermine（破壞）
● underpin（加強、鞏固）
● understand（理解）
● understudy（充當替手）
● undertake（擔任、著手）
● outline（略述）
● outrage（虐待，侵害）
● outspread（伸展）