1．gh在詞首時,讀作/g/.
例：ghost/gəust/
2．詞首為字母1,且后跟字母組合augh時,gh讀作/f/.
例：laugh/la:f/,laughter/'la:ftə/
3．詞尾為字母組合ough時,gh讀作/f/.
例：enough /i'nʌf/,cough/kʌf/,rough/rʌf/,tough/tʌf/
二、gh在下列五種情況下不發(fā)音
1．gh 在元音字母i后不發(fā)音.
例：bright/brait/,fight/fait/,frighten/'fraitn/,high/hai/,light/lait/,might/mait/,night/nait/,right/rait/,sight/sait/,slight/slait/
2．gh在元音字母組合ei和ai后不發(fā)音.
例：eight/eit/,eighth/eitθ/,neighbor/'neibə/,straight/streit/,weigh/wei/,weight/weit/
3．gh在字母組合ought中不發(fā)音.
例：bought/bɔ：t/,brought/brɔ：t/,fought/fɔ：t/,thought/θɔ：t/
4．字母組合augh前面不是1時,gh不發(fā)音.
caught/kɔ：t/,daughter/'dɔ：tə/,naught/nɔ：t/,naughty/'nɔ：ti/,taught/tɔ：t/
5．詞尾為ough的詞,如以上所述,有的發(fā)/f/,但有時也不發(fā)音.
例：although/ɔ：l'ðəu/,plough/plau/,through/θru：/,though/ðəu/,thorough/'θʌrə/
注意：若gh不是字母組合,而是分屬于前后兩個不同的音節(jié)時,不適合以上規(guī)則.
例：dininghall/'dainiŋhɔ：l/
1．在th后以字母-er結(jié)尾的單詞中,th讀濁輔音/ð/.例：altogether/ɔ:ltә'geðә/,farther/'faðә/,feather/'fe ðә/,
whether/'we ðә/,either/'aiðә/,gather/'gæðә/
2．一般情況下,在代詞、冠詞、介詞、連詞或副詞中的字母組合th,讀濁輔音/ð/.例：within/wi'ðin/,without/wi'ðaut/,these/ði:z/,therefore/'ðeәfɔ:/,
al-though/ɔ:lðәu/,those/ ðәuz/,the/ ðә/,thus/ ðas/發(fā)音特殊的單詞：through/θru:/,throughout/θru:'aut/
3．字母組合th在數(shù)詞（包括基數(shù)詞和序數(shù)詞）中讀清輔音/θ/.例：three/θri:/,thirty/'θә:ti/,thirteen/'θә:'ti:n/,third/ θә:d/,fourth/fɔ:θ/,fiftieth/'fiftiiθ/,thousand/'θauzәnd/,hundredth/'handrәdθ/
4．除上述單詞外,一般位于詞首的th讀/θ/.例：theatre/'θiәtә/,thick/θik/,thin/θin/,throat/θrәut/,theory/'θiәri/,thrust/θrast/,thread/θred/,thorough/'θarә/,Thursday/'θә:zdi/
5．以th結(jié)尾的單詞,th讀清輔音/θ/.例：truth/tru:θ/,worth/wә:θ/,breath/breθ/,both/bәuθ/,cloth/klɔθ/,path/pa:θ/,wealth/welθ/,length/leŋθ/,strength/streŋθ/發(fā)音特殊的單詞,例：smooth/smu:ð/
6．在復合詞中,th的讀音與在原詞中的讀音相同.例：something / 'samθiŋ/,anything/'eniθiŋ/,nothing/'naθiŋ/還有前面提到的within,without等.
7．其他無規(guī)則可循的詞分列如下：maths/mæθs/,arithmetic/ә'riθmәtik/,clothing/klәuðiŋ/,clothes/klәuðz/,southern/'saðәn/,northern/'nɔ:ðәn／,worthy/'wә:ði/,author/'ɔ:θә/,sympathy/'simpәθi/