Dual and plural words

[zaba]

How does on distinguish between a DUAL word and a PLURAL word?
I guess 'pair' (in English) is DUAL, correct?
I guess English has no plural words, either, no? (so poor this language!)

[lx]

In order to distinguish between a category of DUAL and a category of PLURAL, we need to know the specific definition being invoked here. It's not enough to assume this category distinction 'just exists' and then apply it to various lexical items in a language without being able to analyse the semantics against some logically-sound definition being assumed.

Regarding the no plural-only words, where would you put riches, remains, jitters, jeans, clothes, suds etc?

[zaba]

Let me try another way:

What sort of thing do dual and plural words have in common?
What sort of thing do dual and plural words not have in common?

[lx]

Let me try another way:

What sort of thing do dual and plural words have in common?
What sort of thing do dual and plural words not have in common?

I'm definitely interested in having a go at answering your question and exploring this. It's just that the pedant in me needs to have a clear understanding of exactly what definition these dual and plural words are being identified by. It needs to be clear exactly what words are under discussion to be sure the correct distinction is being made. I'm also asking as a way to gauge whether you're assuming such a definition or if this is more of a loose idea of a possible distinction that doesn't have a solid definition in your question just yet (which can easily be fixed).

I know this might appear a bit circular (i.e. tell me the definition of something you're trying to define) so it's probably best to answer it with a question or a small sample group of the words you're thinking about.

What words to you are DUAL and not PLURAL?
What words to you are PLURAL and not DUAL?

Then, with a clear understanding of the distinction you're making, we can expand out and make some more generalisations and answer the first question you posted.

[Daniel]

I am very confused by your use of the terms "dual" and "plural".

Are you talking about grammatical number? If so, then your definition of "word" is very important. A word might mean a lexical item or lemma, in which case lexical items do not have number-- "dog" and "dogs" are the same lemma. A word might also refer to a grammatical word or word form, such as "dog" or "dogs", and they do have different number.

Dual is used just like plural. When there is one of something, you use singular. When there are two, you use dual. When there are more than two, you use plural.

English has singular and plural. There are also mass nouns, which do not distinction between singular and plural, and there are some unusual plural-only words like "scissors" which behave anomalously.
There is no dual in English.

Other languages also have other categories such as trial (3) and possibly quadral (4; very uncommon), as well as "multal" (many) and "paucal" (few). For some large numbers, a different system may be used-- for example after 10 in Arabic the singular is used again. (In that case, the singular might be called a "general number", rather than strictly singular.)

The way to test these is simple. Take a simple countable noun like "house" or "man" and then ask a speaker how to describe a scenario in which there are 1, 2, 3, 5, 10, 20, 100, etc.

http://en.wikipedia.org/wiki/Grammatical_number

[Jase]

You cannot give examples of duals in English for the simple reason that there is no specific form for duals in English. In classical Greek, verbs were marked for dual; in Hebrew nouns are thus marked. I can give you examples, if it will help.