At present, no comprehensive dialectology has been done in the Tagalog-speaking regions, though there have been descriptions in the form of dictionaries and grammars on various Tagalog dialects. Ethnologue lists Lubang, Manila, Marinduque, Bataan, Batangan, Bulacan, Tanay-Paete, and Tayabas as dialects of Tagalog.
However, there appear to be four main dialects of which the aforementioned are a part; Northern (exemplified by the Bulacan species), Central (including Manila), Southern (having the Batangan dialect as of prime example), and Marinduque.
Some example of dialectal differences are:
* Many Tagalog dialects, particularly those in the south, preserve the glottal stop found after consonants and before vowels. This has been lost in standard Tagalog. For example standard Tagalog ngayon (now, today), sinigang (stew), gabi (night), matamis (sweet), are pronounced and written ngay-on, sinig-ang, gab-i, and matam-is in other dialects.
* In Morong Tagalog, [r] is usually preferred over [d]. For example, bundók, dagat, dingdíng, and isdâ become bunrok, ragat, ringring, and isra.
* In many southern dialects, the progressive aspect prefix of -um- verbs is na-. For example, standard Tagalog kumakain (eating) is nákáin in Quezon and Batangas Tagalog. This is the butt of some jokes by other Tagalog speakers since a phrase such as nakain ka ba ng pating is interpreted as "did a shark eat you?" by those from Manila but in reality means "do you eat shark?" to those in the south.
* Some dialects have interjections which are a considered a trademark of their region. For example, the interjection ala eh usually identifies someone from Batangas while as does hani in Morong.
Perhaps the most divergent Tagalog dialects are those spoken in Marinduque. Linguist Rosa Soberano identifies two dialects, western and eastern with the former being closer to the Tagalog dialects spoken in the provinces of Batangas and Quezon.
One example are the verb conjugation paradigms. While some of the affixes are different, Marinduque also preserves the imperative affixes, also found in Visayan and Bikol languages, that have mostly disappeared from most Tagalog dialects by the early 20th century; they have since merged with the infinitive.
Standard Tagalog: Susulat sina Maria at Fulgencia kay Juan.
Marinduque Tagalog: Másúlat da Maria at Fulgencia kay Juan.
"Maria and Fulgencia will write to Juan."
ST: Mag-aaral siya sa Ateneo.
EM: Gaaral siya sa Ateneo.
"He will study at Ateneo."
ST: Magluto ka!
EM: Pagluto ka!
ST: Kainin mo iyan.
EM: Kaina mo yaan.
ST: Tinatawag ngâ tayo ni Tatay.
EM: Inatawag nganì kitá ni Tatay.
"Father is calling us indeed."
ST: Tutulungan ba kayó ni Hilarion?
EM: Atulungan ga kamo ni Hilarion?
"Will Hilarion help you (pl.)?"