Comparing the Vocabularies of Native and Non-Native Speakers

Sep 11, 2018

Woman Studying

In 2014, Voiance published a blog post focused on the challenge of learning English as an immigrant to the United States. Our goal was to highlight the work that non-native English speakers put into learning the language, and to dispel the notion that US residents who do not speak the language perfectly have somehow been negligent. 

The post has since become one of our most popular blogs, garnering thousands of views in the past year alone. And in a time when the nation struggles to reach a consensus on immigration, its message appears more poignant than ever. Here's an updated version of the blog post:

Many immigrants who come to the US become quite proficient and fluent in English. For the 60 million who speak another language at home, nearly 60% report that they speak English very well.

But how does that compare to the abilities and knowledge of a native speaker—especially in situations that require specific vocabulary, such as legal or medical scenarios?

In 2013, researchers from the independent American-Brazilian research project presented the results of a multiyear test that measured “vocabulary sizes according to age and education, particularly to compare native learning rates with foreign language classroom learning rates.”

The vocabulary test study

The test takes a random sample of words out of the extensive 45,000 English vocabulary and arranges them in order of grade-level difficulty. Test takers then select the ones that they understand the definition for, not just recognize. The test then creates a second list of words, narrowed down from the first to where the test taker’s general reading level is, and tests a second time before producing the results.

Even with intensive study, how many words do non-native speakers know?

The researchers found that native English-speaking adults understand an average of 20,000 to 30,000 vocabulary words, and native speakers learn about one word a day from ages 16 to 50.

In contrast, non-native speakers living in English-speaking countries for many years learn 2.5 words a day, over twice the rate of native speakers. Even with that breakneck speed, researchers found that adults know on average 10,000-20,000 words less than their native counterparts, or a native English speakers’ 8- to 14-year-old vocabulary level. 

The value of providing language services

Learning a language is a lifelong pursuit: even native speakers learn a new word every day on average. Critics of immigration often say that if only immigrants took the time to learn the language of the country they immigrated to, they would integrate better. This study shows that learning a language to total fluency takes years of study and dedication, and a non-native speaker may still miss critical vocabulary.

The takeaway is this: even if certain customers appear to be fluent and proficient in English, there may be moments when they will need and want a professional interpreter to help them, such as in jargon-heavy legal or financial scenarios. An interpreter can be, and often is, a lifesaver.

Want to learn more about how providing quality, comprehensive language services to non-native speakers can impact your organization's bottom line? Download our ebook:

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Topics: The More You Know, Over-the-Phone Interpretation, multilingual support

Written by Regina Wetzel

An experienced researcher, writer, and editor on language services-related topics, specializing in how language works and translation services.