No. There is no conjugation in Vietnamese and thus the infinitive of a verb is just the verb itself.
Chia by itself means to divide.
Yes, oftentimes the nominalisation of verbs means that you end up with a 2-morpheme compound. For instance:
Ăn uống = to eat + to drink = consuming (n.), dining (n.)
In a lot of cases it harmonises a Northern one with a Southern one:
Bơi lội = to swim (Northern) + to swim (Southern) = to swim, swimming (n.)
This is also common for nouns:
Chăn mền = blanket (Northern) + blanket (Southern) = blankets
Chén bát = small bowl (Southern) + bowl (Northern) = bowls
Oh, that word forming is familar. Many modern Chinese words are combinations from Ancient nouns spoken in different regions.
"Sẻ", as a noun, means "sparrow". When being a verb, it means "to divide" or "to share". http://tratu.coviet.vn/hoc-tieng-anh/tu-dien/lac-viet/V-A/s%E1%BA%BB.html
I've read a number of posts in different discussions, where people say the Southern dialect and Northern dialect. I do not see how they could be dialects. As far as I understand it, it is mainly a difference in a limited number of vocabulary and slight difference in tone usage and also a small difference in the pronunciation of a few letters. Like here in China where I live, we have Mandarin and Cantonese. They are very similar as Cantonese is a dialect of Chinese but Mandarin speaker can not understand Cantonese (without having first learned it). (Seems I've heard Cantonese has been recently declared a full language rather than just a dialect.) However, The South and North can understand each other with little trouble. It would be like saying the Texas accent is a Dialect. :) Looking forward to reading the comments.
The difference between language and dialect (or language variety) is mutually intelligibility (whether two groups of people can understand each other). Different languages are not mutually intelligible, and different dialects are mutually intelligible. This means North and South Vietnamese are dialects of Vietnamese, and Texan English is a dialect of English.
Technically, Chinese is not a (single) language but a family of languages that includes Cantonese (technically a dialect of Yue Chinese) and Mandarin. Cantonese and Mandarin are not dialects but separate languages since they are not mutually intelligible, as you've mentioned. They are similar in some aspects since they've derived from the same language, but so are French, Italian, and Spanish which are derived from Latin.
Not quite, mutual intelligibility is not the criterion. Fact is, in linguistics there is no clear definition of what constututes a dialect and what constitues a language. And mutual intelligibility is a scale, not a yes-no issue. That's why linguists usually speak of "speech varieties" or "language varieties". It is usually tradition and politics that decides what is called a language and what is called a dialect in colloquial speech. But in linguistics this distinction usually has no base.
Would that make American English a dialect of UK English and 'Texas speak' a sub-dialect of that? :)
There are a number of dialects of English in the United States and even more in the UK.
Interesting. I've always just known them to be accents rather than dialects. Seems so strange to call them dialects. Ie: Texas accent. I've never heard anyone say "Texas Dialect"
As I have usually heard the terms used, the accent refers simply to the way words are pronounced. The same single word could be pronounced in a Texas, California, Yorkshire, or Newfoundland accent, for instance. The dialect refers not only to the phonology, but the local peculiarities of grammar and vocabulary.
In the case of Texas vs New York, even "dialect" seems too strong a word to use, where "accent" seems more accurate, since most differences are pronunciation and mannerisms. I would expect "dialect" to be more properly applied to things like Queens English vs Ebonics, or American English vs Elizabethan English, for example (except that I'm sure there's a completely different term for when one is a descendant of another, such as Elizabethan English and American English).