Similar to any other spell checker in any language, VSpell checks the word against a built-in dictionary of Vietnamese words. Even if the word in question does not exist in the dictionary, VSpell can suggest the possible replacing words by looking at the sentence and its context. Further, VSpell allows the users to choose, add and revise the personal dictionary.
Linguists have generally agreed that Vietnamese is a monosyllabic language. Not surprisingly, the single Vietnamese words number only about seven thousand (7,000). Thus, even taking into account the eight diacritical variations, the spelling of a Vietnamese single word is fairly simple. However, to make up for the lack of words, the Vietnamese language consists of more than thirty two thousand (32,000) combinations of those seven thousand single words. Each combination consists of two single words (not attaching to each other) and has a specific meaning which can be related to the original component words or not at all.
As a result of this language structure, users of the Vietnamese language in word processing often encounter problems associating with a two stage problem that we shall term the "usage/spelling" problem. First, because there are relatively few single words and simple spellings, many times a user can spell a single word correctly but in an incorrect context. Then, as the correctly spelled single word is used in an incorrect context, it becomes a misspelled word. However, to a normal spell checker, that word would still remain a correctly spelled word.
This two stage "usage/spelling" problem is exacerbated when applied to double or compound words. Because there are over thirty thousand double words which comprise two unattached single words in the Vietnamese language, the possibilities of a correctly spelled but incorrectly used single word component of those double words increase significantly.
To solve this peculiar problem, VSpell has special algorithm features which detect all common "usage/spelling" errors in both single and double words. It then explains and suggests the correct words in all situations.
Since the current Vietnamese writing is a fairly new developed writing system, there is a lack of consensus on a standardized writing style and in some cases, word usage. When confronted with such circumstances, VSpell allows users to select either style or usage of their preference.