John, As an expat living in the Philippines, more precisely in the Visayas, learning Tagalog wouldn't serve much purpose beyond being able to understand the news programs on TV, because the local population here doesn't use Tagalog on an every day basis but speaks Cebuano (Bisaya). Bisaya isn't really a dialect of Tagalog (although there are certain similarities), it is a separate language (with Spanish and English influences). When I moved here I made an effort to learn Bisaya, but after 6 years I didn't get much past knowing some phrases and words. In part that's because I (and many others) moved here as a pensioner, not as a young man needing to make a living here, in part it's because many here speak at least some English, which influences how much effort one is willing to make to learn the local language. Another issue is that Cebuano doesn't (seem to) have much structure or grammar, which makes it harder to learn. When interacting with people it does help if you can wish them a good day or ask how they are in their own language though, and judging by the surprise I encounter when doing so, most expats didn't make any effort at learning the language at all. I do have one friend here who has lived in Negros for 4 decades or so (Flemish guy) and he speaks Cebuano fluently. Obviously, people who speak English as their native language are at a disadvantage anyway, because for most of them their language being by far the dominant one all over the planet means they've never had to bother learning another language. Being Dutch helps in that regard, I learned English, French and German in school and used all three extensively during my working years.
How many Filipinos speak tagalog ? I posted on here a long time ago about my experience when i made an effort to learn the language when i first came 13 years ago so i won't repeat any of that but what i will say is that life would be easier for filipinos if they gave up on the many different dialects used in their country and just used English. All official government documents are in English and i remember recently of a professional driver here complaining he could not pass the new driving refresher exam as it was in English, also i have spoken to schoolteachers here who can hardly speak or understand English yet part of their job is to teach English, so what chance do the children have ?
Well, try telling the numerous people in the Netherlands that they need to stop speaking their dialect/language in favour of the official Dutch. You'd have multiple revolutions on your hands if the Frisians can't speak Frisian anymore, the east of the country can't speak their Lower-Saxon dialect anymore, etc. etc. Same would happen in the UK if the Welsh and Scots were told they can't speak their language/dialect anymore, and in Germany if Plattdeutsch would no longer be allowed. Same in Switzerland with 4 different languages, Belgium with 3. Russia and China have many more languages inside their borders than most other countries, but even decades of authoritarian and repressive rule hasn't been able to snuff these out.
After 6 yrs in residence, i have great respect for the Filipinos who are tri-lingual, Bisayan, Tagalog, and English. Trying to force english is like telling the UK that they should give up irish/wales/cockney/scots/upperclass english and only speak Nigerian.... Or the US to give up Boston/New Yawk, Southern, Midwest and only speak Spanish.. huh??? I speak "gamay" bisayan, and know a friend who speaks a bit of bisayan, a lot of tagalog, and grew up with english. I have noted a distinct attitude change among Filipinos when you use even just some bisayan. I also remember from 70 yrs in the states that virtually all Filipinos in the states are very fluent in english, unlike some other immigrants who can be there for 5 decades and speak no english, or expats to Mexico who speak zero spanish after years, and associate with only other ex-pats. I hope this country never looses it's identity, although i sometimes wish that Filipino time might become extinct <grin>...