Natural Language Processing · TEE · mocks

Q1A · NLU and NLG

Timed practice · Solved final paper · December 2025

TEE · actual previous paper · 100 marks · 180 minutes

Question. Differentiate between Natural Language Understanding (NLU) and Natural Language Generation (NLG) in NLP with suitable examples. [5 marks]

Answer

Natural Language Understanding (NLU) interprets language to identify its meaning, intent and relevant information. Natural Language Generation (NLG) produces language that expresses information in a useful form.

Basis	NLU	NLG
Direction	Language → meaning or structured information	Meaning or structured information → language
Typical input	A user utterance, document or sentence	Facts, a database record, a prompt or a representation
Typical output	Intent, entities, sentiment or a semantic representation	A sentence, explanation, summary or dialogue response
Main difficulty	Resolving ambiguity and context	Choosing accurate content and producing coherent, fluent wording

Example: a weather assistant

User: “Will it rain in Mumbai tomorrow?” NLU recognises a weather-query intent, the location Mumbai and the date tomorrow. After a weather service supplies the forecast, NLG produces “Rain is likely in Mumbai tomorrow; carry an umbrella.”

User language NLU: identify request Retrieve forecast NLG: express answer

The two functions often work together in a chatbot. Understanding the request and wording the reply are separate tasks; fluent generation alone does not prove correct understanding.

Yaad rakho: NLU mein meaning nikalo; NLG mein meaning ko sentence banao.