The endings -able, -ion, -er, -or, -ance, -ence, -ous, -ish, and -al are generally used to form adjectives and nouns. Here are some guidelines about how they affect the spelling of the word to which they're added:
-able, -ion, -er, -or, -ance, -ence, -ous, -ish, 和-al常常充當名詞和形容詞的後綴。以下這些規則指出了後綴對單詞的影響:
When you're adding one of these endings to a word that ends with a consonant, the spelling is often straightforward:
當原本的詞彙是以輔音結尾，一般直接添加後綴。
Adapt(vi. 適應), adaptable(adj. 適合的;能適應的;可修改的)
Addict(vt. 使沉溺;使上癮), addiction(n. 上癮，沉溺;癖嗜)
Mountain(n. 山;山脈), mountainous(adj. 多山的;巨大的;山一般的)
Black(n. 黑色;黑人;黑顏料), blackish(adj. 帶黑色的)
If you add one of the endings to a word that ends in an e that isn't pronounced, drop this final e:
如果單詞結尾有不發音的e，則去掉結尾的e再加後綴：
Inflate(vt. 使充氣;使通貨膨脹), inflation(n. 膨脹;通貨膨脹;誇張;自命不凡)
advise(vt. 建議;勸告，忠告;通知;警告), advisable(adj. 明智的，可取的，適當的)
dance(n. 舞蹈;舞會;舞曲), dancer(n. 舞蹈家;舞蹈演員;舞女;跳舞者)
The exceptions to this rule are words that end with a 『soft』ce or ge sound:
這條規則在以ge、ce結尾時例外，不去掉結尾的e：
Notice(n. 通知，布告;注意;公告), noticeable(adj. 顯而易見的，顯著的;值得注意的)
Courage(n. 勇氣;膽量), courageous(adj. 有膽量的，勇敢的)
Advantage(n. 優勢;利益;有利條件), advantageous(adj. 有利的;有益的)
When you add one of these endings to verbs ending in a vowel plus l, you need to double the l:
當單詞以l結尾，需要雙寫l+後綴
Counsel(n. 法律顧問;忠告;商議;討論;決策), counsellor(n. 顧問;參贊;輔導員(等於counselor);律師;法律顧問)
Excel(vt. 超過;擅長), excellent(adj. 卓越的;極好的;傑出的)
Double the final consonant when adding these endings to verbs that end with a single vowel plus a consonant, when the stress is at the end of the verb:
當單詞以單個元音+輔音結尾，並且重音在單詞末尾，雙寫末尾的輔音再加後綴:
Refer(vt. 涉及;委託;歸諸於;使…求助於), referral(n. n. 參照;提及;被推舉的人;轉診病人)
Begin(vt. 開始), beginning(n. 開始;起點)
Forget(vt. 忘記;忽略), forgettable(adj. 可忘記的;容易被忘的)
Don't double the final consonant, if the word ends with a single vowel plus a consonant, and the stress is not at the end of the word:
當單詞以單個元音+輔音結尾，並且重音不在單詞末尾，不要雙寫末尾的輔音，直接加後綴:
Visit(n. 訪問;參觀;逗留), visitor(n. 訪問者，參觀者;視察者;候鳥)
Common(n. 普通;平民;公有地), commoner(n. 平民;自費學生;下議院議員)
If the word only has one syllable and ends with a single vowel plus a consonant, double the final consonant:
如果這個詞是單音節詞，且以單個元音+輔結尾音，雙寫最後的輔音:
Stop(n. 停止;車站;障礙;逗留), stoppable(adj. 可停止的)
dim(n. 笨蛋，傻子), dimmer(n. [車輛] 調光器;光暗掣;衰減器)
Don't double the final consonant if the verb ends with two vowels plus a consonant:
雙元音加輔音結尾，不要雙寫最後的輔音：
Sleep(n. 睡眠), sleeper(n. 臥車;臥鋪;枕木;睡眠者)
Treat(n. 請客;款待), treatable(adj. 能治療的;好對付的;能處理的)
In British English, when you add the endings -ous, -ious, -ary, -ation, -ific, -ize, and -ise to a word which ends in -our, you need to change the -our to –or before adding the ending:
在英式英語中,當單詞以-our結尾，在單詞後添加-ous, -ious, -ary, -ation, -ific, -ize, 或–ise後綴時，需要先將our改寫成or再添加後綴：
Humour(n. 幽默(等於humor);詼諧), humorous(adj. 詼諧的，幽默的;滑稽的，可笑的)
Glamour(n. 魅力，魔力;迷人的美), glamorize(vt. 美化;使有魅力)
But when you are adding other endings, the -our spelling stays the same:
但是當你添加其他的後綴時,拼寫保持不變:
Colour(n. 顏色;風格;氣色，面色;外貌), colourful(adj. 鮮豔的;生動的;色彩豐富的;富有趣味的)
Favour(n. 偏愛;贊同;善行), favourite(n. 特別喜愛的人(或物))
（編輯：何瑩瑩）