The English spoken in Ireland is different from that of Northern Ireland. In fact, the English spoken in Ireland and Northern Ireland varies from one region to another. Nevertheless, the two varieties are clearly distinct.
The English of Ireland and Northern Ireland is rhotic. The /r/ is pronounced in all positions. North Dublin, however, has low rhoticity. This is especially true when the /r/ is in an unstressed syllable.
The intervocalic /d/ and /t/ are usually flapped in Northern Ireland. In Ireland, this is also possible, but many speakers from Ireland use intervocalic plosives. However, the voiceless /t/ can become voiced.
The vowels /o/ and /e/ are pronounced as monophthongs. This is not the case in many other varieties of English. In Dublin, however, these vowels are diphthongs.
The foot/strut split, a historical development which resulted in different vowels in foot and strut, definitely applies to Northern Ireland. In Ireland, however, many speakers use the foot vowel in words which do not have it in Standard English. This is especially true in North Dublin.
The intonation of Northern Ireland is often identified by its rising intonation. This intonation is also used in declarative statements. This is in contrast to the English of Ireland which does not use rising intonation in declarative statements.
The /l/ tends to be light in all positions, but many speakers in Dublin have velarized laterals syllable-finally. These velarized laterals are also found in many other varieties of English. They include RP and American English.
The interdental fricatives represented by the letters th are often pronounced as plosives in Ireland. In Northern Ireland, though, they are not pronounced as plosives. They are always pronounced as fricatives.
In Northern Ireland, words such as raise/rays and nose/knows are not pronounced identically. As in Scottish English, the words with affixes have longer vowels. The vowels of rays and knows are longer than the vowels of raise and nose.
Another difference is that words such as boot and goose are pronounced with a central vowel in Northern Ireland. The vowel is more advanced than the one used in Ireland. The vowel used in Northern Ireland resembles that of Scotland.
Though the English of Ireland and Northern Ireland share many similarities, they can be distinguished. The English of Northern Ireland has many influences from Scottish English. In Ireland, the English has been influenced more by the Irish language.