dear sir i would like to know abstract noun for certain common nouns eg agent ,thief,pilgrim,glutton.

Not every common noun has a corresponding abstract noun.

http://www.google.com/search?q=common+abstract+nouns&oq=common+abstract+nouns&aqs=chrome.0.57j0l3j62l2.4254j0&sourceid=chrome&ie=UTF-8

There are two that I can see right away:

thief (common) <~~thievery (abstract)

glutton (common) <~~ gluttony (abstract)

What can you say about the others?

Certainly! To find the abstract noun for a given common noun, you need to think about the qualities, traits, or concepts associated with that noun. Here are some examples for the common nouns you provided:

1. Agent:
- Abstract noun: Agency
Explanation: The abstract noun "agency" refers to the quality or state of being an agent, and it represents the abstract concept of someone having the power to act or make decisions.

2. Thief:
- Abstract noun: Theft
Explanation: The abstract noun "theft" represents the concept of stealing or the act of taking someone's property without permission or unlawfully.

3. Pilgrim:
- Abstract noun: Pilgrimage
Explanation: The abstract noun "pilgrimage" represents the concept of a journey or religious excursion made by a pilgrim for spiritual or religious reasons.

4. Glutton:
- Abstract noun: Gluttony
Explanation: The abstract noun "gluttony" represents the concept of overindulgence or excessive eating and drinking.

Remember, abstract nouns are intangible ideas or qualities, so they represent things that cannot be perceived by the senses.