pressure and suddenly releasing the air.They can be used at the beginning middle and end of words.The following are some of the allophonic variations of/p/and/b/. Allophonic variations of/p/: Allophone Occurrence Example p鬥 Aspirated release in initial word and stressed positions poke p- Unreleased in word final position topten [p Unaspirated release in clusters,esp.after/s/ spot p Lengthening.when an arresting /p/is followed by a releasing /p Stop Pete Nasal release,before a syllabic nasal Stop him. Allophonic variations of/b/: Allophone Occurrence Example [b-] Unreleased in word final position rob [b:] lengthened when an arresting /b/is followed by a releasing /b/ Rob Bob Nasal rese sonance,before a syllabic nasal Rob him. /t/and /d/ The /t/sound is one of the most frequent in English and occur in all three positions at the word many productive sound in the la number of varieties that /t/has.You pronounce them by blocking the airstream with the tongue and upper gum ridge,building up air pressure and suddenly releasing it. The following are some of the allophonic variations of/t/and/d/: Allophonic variations of /t/ Allophone Occurrence Example ftHI Aspirated release in word initial and stressed positions tape Unreleased in word final position t Unaspirated release n consonant cluster,esp.with/s/ stop o Dentalized before/ eighth to Nasal release,before a syllabic nasal button Flapped.intervocalically letter Glottal stop.before syllabic [n]or[] buttonYou pronounce the /p/ and /b/ by stopping the airstream with you lips, building up pressure and suddenly releasing the air. They can be used at the beginning, middle and end of words. The following are some of the allophonic variations of /p/ and /b/. Allophonic variations of /p/: Allophone Occurrence Example [p] Aspirated release in initial word and stressed positions poke [p-] Unreleased in word final position top ten [p ] Unaspirated release in clusters, esp. after /s/ spot [p:] Lengthening, when an arresting /p/ is followed by a releasing /p/ Stop Pete. [ ～ P ] Nasal release, before a syllabic nasal Stop him. Allophonic variations of /b/: Allophone Occurrence Example [b-] Unreleased in word final position rob [b:] lengthened when an arresting /b/ is followed by a releasing /b/ Rob Bob. [ ～ b ] Nasal resonance, before a syllabic nasal Rob him. /t/ and /d/ The /t/ sound is one of the most frequent in English and occur in all three positions at the word level. It has many variations and is a very interesting and productive sound in the language. /d/ is not as frequent in English nor does it have the number of varieties that /t/ has. You pronounce them by blocking the airstream with the tongue and upper gum ridge, building up air pressure and suddenly releasing it. The following are some of the allophonic variations of /t/ and /d/: Allophonic variations of /t/: Allophone Occurrence Example [t] Aspirated release in word initial and stressed positions tape [t-] Unreleased in word final position coat [t ] Unaspirated release in consonant cluster, esp. with /s/ stop [t～] Dentalized before /θ/ eighth [t(] Nasal release, before a syllabic nasal button [r] Flapped, intervocalically letter [] Glottal stop, before syllabic [n] or [l] button