OK, I know there are hundreds, perhaps thousands of different languages, dialects and pronunciation variations in the Philippines. I'm just curious about one word though...what is the difference or different usage or different grammar for these:

intindihan
maintindihan
naiintindihan

Is this a mainly 'Tagalog' word? Or is it used within many of the other languages/dialects? Is it mainly on Luzon? or also down to the Visayas and Mindanao?

also, is arok and maarok roughly the same thing?

I'm from the states and I'm planning on moving next year to the Philippines to learn more about the business but the problem is I don't know how to speak tagalog, i know some words but not too much. I'm 26 years old and I'm willing to learn.
He is a electrical supplier for companies around the Visayas.

yeah,how come tagalog is the national language of the philippines.?when the visayas and mindanao and also part of palawan speak a language similar to cebuano....no offense:)