What Is Natural Language Understanding?
What Is Natural Language Understanding?
Natural language understanding (NLU) is the ability of a computing system or software to understand human language. It allows the software to recognize chat intent and sentiment and provide highly engaging user experiences through lifelike conversational interactions. For example, assistants like Alexa respond to human voice, and AI-powered chatbots participate in text-based conversations. Natural language understanding enables these systems to take any human-generated conversational input, convert it into internal computer language syntax, and act upon the input. Users can naturally interact with machines using the language of their choice.
Why is natural language understanding important?
Businesses extract several benefits from natural language understanding technology.
Increase customer engagement
Natural language understanding is the technology behind automated conversational experiences in contact centers, social media platforms, and mobile applications. You can quickly automate customer service interactions, decrease inquiry response times, and meet customer service expectations at reduced cost.
For example, when customers call a business number, they can interact with an AI chat interface that understands their query and directs them to the right human agent. Interactive voice response (IVR) is another technology powered by natural language understanding that allows customers to use their voice to navigate call menus. It streamlines the initial stages of customer support, saves time, and improves customer engagement.
Enable intelligent search
Natural language understanding plays a key role in intelligent search technology. Intelligent search can understand natural language questions from end users and search through forums and internal knowledge databases to find the specific information needed. Due to NLU, it can summarize and present information from multiple sources in concise paragraphs.
Optimize business operations
Natural language understanding can help automate repetitive tasks, reducing effort and expediting service delivery. For example, you can create flows for common tasks like making payments or sending transaction progress updates. By collecting information upfront, you can also achieve faster troubleshooting. Employees can then use their time on higher-value activities and improve productivity.
Personalize user experiences
Natural language understanding technologies can transcribe user input, identify user intent, and deliver personalized experiences. By integrating NLU with consumer data and behavior patterns, your business can provide unique offers or tailored messages to your customers.
What are natural language understanding applications?
We give some examples of popular natural language understanding applications below.
Virtual assistants
Natural language understanding (NLU) powers virtual assistants like Alexa, enabling them to interpret spoken or written language. These assistants use NLU to understand user queries, extract intent, and provide relevant responses. They can schedule appointments, send emails, or ping APIs to display data about the weather or events planned for the day. Customers can also customize their virtual assistants to improve their personalization services and increase the number of tasks they complete.
Sentiment analysis
NLU-powered sentiment analysis software helps classify reviews, social media posts, and support tickets as positive, negative, or neutral. It analyzes text and spoken language to determine emotion. Companies track sentiments to gauge brand perception, improve customer service, and respond proactively to emerging trends.
Intent recognition
NLU is crucial for recognizing user intent in customer support, chatbots, and search engines. For example, it allows systems to distinguish whether a user wants to book a ticket, request a refund, or seek information, leading to more accurate and context-aware responses. Intent recognition improves chatbot functionality and streamlines customer service scenarios.
How does natural language understanding work?
Natural language understanding takes text as input and interprets it similarly to humans. It works in three main stages.
Tokenization
Tokenization breaks down natural language input into smaller language units, like specific words or unique sounds. It also handles contractions and punctuation. For example, the sentence “I’m going to John’s house!” might be tokenized as:
[“I”, “’m”, “going”, “to”, “John”, “’s”, “house”, “!”] This step helps NLU systems identify sentence and paragraph components.
Lexical analysis
Lexical analysis helps to give specific words their context. It analyzes each token to determine its meaning based on dictionaries, parts of speech, and context. This step helps distinguish between words that have multiple meanings. For example, in the sentence “I left my watch on the table,” the word “watch” could mean:
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A timepiece (noun)
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The act of observing something (verb)
Lexical analysis, aided by context, determines that “watch” above refers to a physical object rather than an action. Another example is handling synonyms. In the sentence “She purchased a new laptop,” lexical analysis recognizes that “purchased” is synonymous with “bought.”
Syntactic analysis
Syntactic analysis determines the overall sentence structure, looking at its syntax to determine how words fit together. It ensures that the sentence follows the syntax rules and identifies components like subject, verb, and object. For example, in the sentence “The quick brown fox jumps over the lazy dog,” a syntactic parser breaks it down into:
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Subject: “The quick brown fox”
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Verb: “jumps”
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Prepositional phrase: “over the lazy dog.”
Syntax and sentence structure also help natural language understanding software understand user intent. Consider the difference between:
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“Can you book a flight to Paris?” (A request to book a flight)
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“Can you tell me if I can book a flight to Paris?” (A request for information about booking)
Syntactic analysis helps NLU tools understand more complex queries and deliver the intended function.
What is the difference between natural language understanding, natural language generation, and natural language processing?
Natural language processing (NLP) is the broad term for all machine learning technologies that analyze and interpret human language.
Natural language understanding (NLU) is one part of NLP that aims to understand the content and context of a sentence to determine its meaning. It helps to process complex sentences or phrases that may have multiple meanings.
Natural language generation (NLG) is the other part of NLP. NLG technologies identify the best words and sentence structures in the response to user input.
To summarize NLU vs. NLP vs. NLG:
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NLU focuses on understanding user input.
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NLG focuses on generating a meaningful response.
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NLP is the umbrella term that includes both NLU and NLG.
Natural language understanding, processing, and generation software are now common in business operations, ranging from customer engagement to business analytics.
What capabilities should you look for in NLU technology?
Modern NLU technology should have the following capabilities.
Generative AI
Generative artificial intelligence refers to large language models trained on vast amounts of data and capable of language processing in ways impossible with traditional NLU technology. It helps to improve user experience and offers a range of new features. For example, NLU with generative AI can:
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Provide automated responses to frequently asked questions.
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Analyze customer sentiment and intents to route calls appropriately.
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Generate conversation summaries to help agents.
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Automatically generate emails or chat responses to common workflows.
This new generation of AI-powered assistants provide seamless self-service experiences that delight customers. NLU technology that uses generative artificial intelligence can write emails based on vocal commands or rapidly summarize conversations.

High-quality speech recognition
Users may have distinct accents or ways of speaking. This speech diversity should not be a restriction for NLU tools. You want an NLU system that learns how users can express their intent based on a few sample utterances. It should understand human speech and deliver the intended response for all demographics.
Context management for multi-turn dialog
Effective NLU tools must store and track temporary contextual information throughout a conversation, understand user inputs in a way that mimics human-to-human interactions, and maintain coherence across multiple exchanges, ensuring a smooth conversational experience.
For example, if a user initiates a hotel booking request with a voice chatbot by saying, “I need a hotel in New York,” the chatbot should:
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Recognize that additional details are needed and respond with relevant follow-up questions such as “For how many nights?” and “What is your check-in date?”
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Retain previous user inputs so that when the user specifies, “Three nights, checking in on March 10,” it correctly associates this information with the New York hotel request.
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Handle pronouns so that if the user continues with “Actually, make it four nights,” the chatbot should understand that “it” refers to the hotel booking.
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Handle implicit references and topic shifts. For example, in a customer service chatbot, if a user asks, “Where’s my order?” and later says, “Can I change the delivery address?” the system should recognize that “the delivery address” refers to the same order previously mentioned.

Ease of implementation
Natural language understanding tools should be easy to build and set up with little technical support. Even non-technical users should be able to set up conversational workflows with NLU software. Look for visual drag-and-drop conversation builders that are easy to design and test.
How can AWS help meet your NLU requirements?
Amazon Lex is a service that builds conversational interfaces using voice and text. It is powered by the same conversational engine as Alexa and advanced generative AI technology to provide high-quality speech recognition and language understanding capabilities. With Amazon Lex, you can:
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Add sophisticated, natural language ‘chatbots’ to new and existing applications.
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Provide automated responses, including automatically generating emails or chat responses to common customer inquiries.
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Generate summaries of conversations to help agents.
Natural language understanding is one of the most challenging problems in computer science. It requires sophisticated AI algorithms to be trained on massive data and infrastructure. Amazon Lex makes such AI technologies accessible to all developers through an easy-to-use, fully managed service.
Get started with natural language understanding on AWS by creating a free account today.
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