A compassionate teacheris a pillar of the education system. Here the underlined part is a/an -

• A compassionate teacher is a pillar of the education system. Here the underlined part is a - Noun phrase.
- - এখানে বাক্যের subject হিসেবে কাজ করেছে বিধায় উক্ত phrase টি noun phrase.

• Noun phrase: 
- A noun phrase consists of a pronoun or noun and any associated modifiers, including adjectives, adjective phrases, adjective clauses and other nouns in the possessive case.
- অধিকাংশ সময়ই, Noun phrase  মূলত: একটি Noun বা Pronoun এর কাজ করে। 

• এছাড়া, অর্থ এবং বাক্যে অবস্থান অনুযায়ী Noun phrase বিভিন্ন ভূমিকা পালন করে ।
- যেমন: 
- Subject হিসেবে - Small children often insist that they can do things by themselves.
- Object of a verb হিসেবে-  To type quickly and accurately is Eugene’s goal.
- Object of a preposition হিসেবে - The Arctic explorers were caught unawares by the spring breakup.
- Subject complement হিসেবে - Frankenstein is the name of the scientist, not the monster.
- Object complement হিসেবে -  I consider Loki my favorite cat.