Batangas Tagalog also known as Batangan is a dialect of the Tagalog language spoken primarily in the province of Batangas and the island of Mindoro ("Batangueño/a" refers to the natives). The dialect is distinctively characterized by a very strong accent and its vocabulary is more closely related to ancient or old-style Tagalog. It is not customary in colloquial Batangan to speak in Taglish or to infuse English terms as the custom is with Manila Tagalog.
Another noticeable difference is the usage of the closed syllable, a practice that has completely disappeared in the Manila dialect. The town of Tanauan is actually pronounced [tan-'a-wan] whereas it would be pronounced as [ta-'na-wan] by other Tagalogs. This is also true with words like matamis, pronounced matam-is and a couple of other more words.
Also, as mentioned above, the dialect spoken in Batangas is more closely related to the ancient Tagalog. Thus the merger of the phonemes [e] and [i] and the phonemes [o] and [u] are prevalent. Also, absent in other dialects is the use of the schwa sound. This incident is common simply because the dialect spoken in the province is spoken faster compared to other dialects.
Something prevalent in the Batangan dialect that is lacking in other Dialects is the sound [ei] and [ow]. However, unlike its English counterpart, this diphthong is sounded mainly on the first vowel and very rapidly only on the second. This is very similar to the [e] in the Spanish word educaciòn and the first [o] in the Italian word Antonio.
And as a proof that the Batangan Dialect is closer to the Old Tagalog than any other dialects, the practice of merging the phonemes /e/ and /i/, as well as /o/ and /u/, are still very noticeable. One can hear the words 'lola' (grandmother) pronounced as if written 'lula'. This is also true with the word 'baboy' (swine), which is pronounced 'babuy'. However, everyone will tell you that you misspelled the words when you use the latter in writing.