How do you decide what verbs to use when dealing with indefinite pronouns that can be singular or plural? (

Answer 1

You are referring, I assume, to the following pronouns:
all, most, some
any, none

The rule is this:
Treat the pronoun as singular (and taking a singular verb form) if you are referring to a total quantity; treat it as plural (with plural verb form) if you are referring to a number of individual items that can be COUNTED.

Examples:

Some of the scenery was destroyed in the fire. (quantity)
Some of the tickets were destroyed in the fire. (number)

Most of our show is hilarious. (quantity)
Most of our singers are excellent musicians. (number)

examples from:
http://www.harmonize.com/Probe/aids/StyleManual/pronouns.htm

Notice that the key word in "some/any/all....of X" expressions is the "X". If this noun is plural the verb form should be plural; if it is singular the verb form is singular. In other words, you could simply lop off the "most of"/"some of", etc. and the verb forms would be the same.

Answer 2

Hm, well are you talking in concern to the english language? Or in a diffrent language.

In some lanugaes you are requiered to conjugate the verbs, or change them depeneding on the type of subject noun you have ( I, you, him/her, we/us, them and plural you.)

In the english language you do not have to alter the following verb with a few exceptions such as; is am are was were be being been have had has seems.

Answer 3

It seems that part of your question is missing.
If not, is it possible to be more specific? I don't think that the verb is affected by the pronoun being single or plural.

Answer 4

if you mean it to be plural, use the plural form of the verb
or vice versa if you mean it to be singular