Do not confuse demonstrative adjectives with demonstrative pronouns. The words are identical, but demonstrative adjectives qualify nouns, whereas demonstrative pronouns stand alone. Demonstrative pronouns can be used in place of a noun, so long as the noun being replaced can be understood from the pronoun’s context.
An indefinite pronoun does not refer to any specific person, thing or amount. It is vague and "not definite". Some typical indefinite pronouns are: all, another, any, anybody/anyone, anything, each, everybody/everyone, everything, few, many, nobody, none, one, several, some, somebody/someone.
In some cases, interrogative pronouns take on the suffix –ever. A few can also take on the old-fashioned suffix –soever, which is rarely seen in writing these days. For example: Whatever; Whatsoever; Whichever; Whoever; Whosoever; Whomever; Whomsoever; Whosever; Interrogative pronouns are very easy to remember and use. Memorize them to make things even simpler.
Each other; One another; Reciprocal pronouns are easy to use. When you want to refer to two people, you will normally use “each other.” When referring to more than two people, for example the students in a lecture hall, you will normally use “one another.” Examples of Reciprocal Pronouns. Reciprocal pronouns help prevent repetition within sentences.