Tagalog is regarded by many as the dominant language of the Philippines despite it not technically being the standard variety. The most significant recent development in the Philippine language situation has no doubt been the rise of Tagalog to a position of dominance among the other native tongues. Tagalog language and varieties of the language are becoming most prominent in the city of Manila, as it is the capital and most densely populated. In Luzon, the Tagalog language is used by the majority of the population. The Tagalog homeland Katagalugan covers much of the central to southern parts of the region. Tagalog is spoken natively in Marinduque and Mindoro.

A few items of vocabulary and grammar were compared with Manila Tagalog, as well as with the Tagalog dialects of Lipa (Batangas), Imus (Cavite), L1l1o (Laguna), and Gumaca (Quezon). The study showed: (1) some words that were similar in form to Manila Tagalog but not in usage or meaning, (2) words and idioms not occurring in Manila Tagalog, (3) phonetic and grammatical differences between Boak Tagalog and Manila Tagalog, and (4) the recurrence of a few idioms in the four Southern Tagalog dialects used as bases for comparison. As a whole, Lopez received the first impression that Boak Tagalog was a “simpler and more imperfect form of the more highly developed Manila Tagalog”. Of special interest was his remark that such provincial forms of speech have originally been the roots of the language, from which forms have sprung and have become standard. These dialects may also be found in remnants of older speech strata.