I remember a particular time when my dorm mates and I were having our fill for dinner. Because our dormitory is specifically made to house students from far flung places – provinces – in the Philippines, it is bound to have dormers speaking different languages. Within this particular time, a Visaya-native was speaking to another Visaya-native in their language when suddenly somebody else laughed at what they were talking about. The thing is, he is not from the Visayas but rather further up, in the north – Nueva Vizcaya.
While we, Tagalog-natives, were dumbfounded of what on Earth the two might be talking about, this guy understood a hint of what the Visaya-speakers were saying. He proceeded to ask someone from his home province, who also happened to be with us that night, and so a word-by-word comparison had been made between them, Ilokano and Visaya, and we were all shocked by how many words are both recognized within the two languages.
It is somewhat curious to note how people from the north (Ilocano) of the Tagalog ethnic groups and the south (Visaya) have words that are known by both. This leads to a notion that somewhat the north and the south had a connection between them: either after both languages had been established or before both had been established.
While some account said that it is easier to learn Visaya if you are Tagalog than if you are to learn Ilocano learning Visaya, the fact that some words can be understood by both Ilocano and Visaya that is not present in Tagalog are still worth-noting. In this context, a disconnection by the Tagalog to both the north and the south could be inferred. This is said to be because some Tagalogs are indifferent to people speaking other languages, that they are not receptive to people other than themselves.
It is believed that the three languages of Tagalog, Cebuano (a dialect of Visaya), and Ilocano shares an ancient Philippine orthography, Baybayin. This could demonstrate that this connection, between the north and the south, had happened before both languages were established. It could mean the propagation of the language progresses in a manner that is cladogenesis. The language of Ilocano and Visaya, could be branches originating from a common progenitor migrating to different location within the Philippines.
In this notion, because this connection happened way before both languages, and thereafter the ethnic groups had been established, assuming that a disconnection of the Tagalogs to both the north and the south would be impossible to happen.
Joel P. Ilao, et. al. Comparative analysis of actual language usage and selected grammar and orthographical rules for Filipino, Cebuano-Visayan and Ilokano: a Corpus-based Approach. Quezon City, 2013.