Intervocalic /t/

General American English realizes what is written as /t/ with the flap of the tongue tip against the alveolar ridge and when it comes between two vowels it turns into /d/. E.g. latter > ladder.

Post nasal /t/

The post-nasal /t/ in words "winter”, “enter" where an unstressed vowel follows, /t/ is not pronounced: winter = winner

Dental and alveolar consonants + / j /

Such combinations of sounds as /nj/ /sj/

/tj/ /zj/

/dj/ /Tj/

/lj/

do not occur in the most varieties of General American English. All those words spelt with u, ew, eu, ui, ue usually have simple /u/. The combination /nj/ and /lj/ are possible in General American if there is an intervening syllable boundary: e.g. January, monument, value.

Palatalization

In General American English palatalization is regular when the following syllable is unstressed. There are a few well-known cases of palatalization before the stressed syllable, e.g. sure, sugar, assure. Received Pronunciation agrees in most cases with general American English but it has the additional possibility of unpalatalization /dj/, /tj/, /sj/, /zj/ in those cases where letter “u” follows, e.g.:

education issue

RP /"edjH'keISqn/ RP /ISH/

GenAm /"eGq'keISn/ GenAm /'IsjH/

A number of place names are unpalatalized in Received Pronunciation and palatalized in general American English, e.g.:

Tunisia Indonesia

RP /tjH'nIzIq/ RP /Indq'nJzIq/

GenAm /tH'nJZq/ GenAm /Indo'nJZq/