A Case for Teaching with Cognates

One myth that persists in education is the idea that a child’s native language is an impediment to English language acquisition and to academic achievement in general. While this unfortunate myth remains present in classrooms and schools across the country, it is not supported by research. Bilingual education actually bolsters academic success and can close achievement gaps between the home and target languages. Despite the promising research findings, 76% of emergent bilingual students learn in ESL or English-only settings and receive little to no instruction in their home language.

Cognate instruction is a powerful instructional tool that is often used in bilingual settings but can also be transposed into an English-only setting. Cognate instruction leverages the Latin roots of both Spanish and English to rapidly advance student vocabulary acquisition. For example, a Spanish speaking student can use their knowledge of the word ‘observación’ to make meaning of the word ‘observation’ in English.

Although the cognate approach has wide research support, many teachers lack the necessary training to meet the linguistic and academic needs of their emergent bilingual students. School districts struggle to meet competing professional development demands and many state-level teacher certification requirements do not include coursework on language acquisition or ESL teaching methods. For this reason, it is imperative that school districts and teacher preparation programs keep cognate instruction at the forefront of their professional development and teacher certification agendas.

Having worked as a bilingual educator in a Spanish dual language setting and now in a transitional bilingual setting, I frequently use cognates to foster cross-linguistic connections for my emergent bilingual students and I have seen firsthand how Spanish-English bilingual instruction positively impacts my students.

When I joined the Teacher Run Experiment Network, I wanted to run a study that would objectively evaluate whether cognate instruction is beneficial to emergent bilingual learners in both a bilingual and English-only instructional setting.


This study compares the efficacy of Spanish-English cognate-based vocabulary instruction to English-only vocabulary instruction in two bilingual Illinois classrooms, which are part of a K-8 Transitional Bilingual Education program. The study participants include eight second-grade and seventeen third-grade emergent bilingual students. Included in the roster of third-grade participants were four students with Individual Education Plans (IEPs). Students received six weeks of targeted vocabulary intervention delivered virtually in small groups. The lesson cycle alternated between English-only vocabulary instruction and Spanish-English cognate vocabulary instruction, thus resulting in three weeks of each intervention. Each week, students were presented with four new vocabulary words chosen from the school’s Wit and Wisdom English Language Arts (ELA) curriculum, so in total, students were presented with twenty-four different vocabulary words. The twenty-four target words for cognate instruction weeks were all Spanish-English cognates while the word list for English-only weeks consisted of twelve Spanish-English cognates and twelve non-cognate English words. 

Lesson delivery for English-only weeks consisted of a Google slides deck containing the target word, an image, and an example sentence. Lesson delivery for Spanish-English cognate weeks consisted of a Google slides deck containing the target word in both languages, an image, and an example sentence in both languages. At the end of each week, vocabulary acquisition data was collected via Google form. Second-grade students were asked to determine whether target words were used correctly in a spoken sentence and third-grade students were asked to write down the definition of each target word. 


Over the course of the six-week intervention, the twenty-five students thoroughly enjoyed learning classroom vocabulary in both English and Spanish. In fact, 80% of the twenty-five students report preferring to learn in either Spanish or in both English and Spanish. Additionally, 84% of the second and third-grade students report preferring to learn new English words in both English and Spanish. This qualitative data gives further credence to the importance of home language instruction for emergent bilingual students. 

As hypothesized, after the six-week vocabulary intervention, the second and third-grade emergent bilingual students obtained higher vocabulary acquisition scores on average during bilingual weeks when compared to scores from English-only weeks.

Across English-only weeks, the average student score was 2.76, whereas the average score for cognate weeks was 3.14. The difference in average student scores indicates a marginal instructional benefit offered by cognate-based bilingual vocabulary instruction when compared to English-only vocabulary instruction. Additionally, fifteen out of twenty-five students obtained a higher average score during cognate weeks when compared to English-only weeks. The mean gain for cognate instruction was 0.35 points with a standard deviation of 0.61. 

When comparing student performance by condition, again, cognate-based bilingual instruction marginally outshone English-only instruction: students had a higher percentage of words correct throughout the cognate-based vocabulary intervention. When distinguishing performance within the English-only intervention results, students were able to correctly define and recall cognate words at a higher percentage when compared to the recall of non-cognate words. This result indicates that an emphasis on cognates enhances vocabulary acquisition for emergent bilingual students even when the primary language of instruction is English. Overall, the data signals that cognate-based bilingual vocabulary instruction provides an academic advantage for emergent bilingual elementary-aged students. 


This study reinforces the notion that emergent bilingual students derive positive instructional benefits from Spanish-English cognate instruction. The research stating that native-language instruction is essential to the academic success of emergent bilingual students is not new, however, classroom and school implementation lags. Further complicating matters is the fact that the majority of emergent bilinguals attend schools with limited home language instruction or support. Additionally, it’s no secret that the majority of teachers in the United States are monolingual English speakers – only one in eight American teachers speak a language other than English. Multilingual teachers are in high demand but in short supply. 

Despite these limitations, emergent bilingual students still need linguistically affirming classrooms in which to thrive. Looking back at the data, the results indicate that an emphasis on cognates enhances vocabulary acquisition for emergent bilingual students even when the primary language of instruction is English. Intentional and explicit cognate instruction is a simple, effective, and accessible practice that can be leveraged by both monolingual and multilingual educators. For this reason, all teachers of emergent bilinguals must receive professional development on cognate awareness and explicit cognate instruction for all core subject areas. Armed with this new knowledge, our multilingual learners can benefit from the cognate advantage, no matter the classroom.


Irene Post is a bilingual education teacher in Chicago, with 10 years of experience. She received her bachelor’s degree in education and psychology from Columbia University and holds a master’s degree in literacy from Bank Street College of Education. In addition to working with young students, Irene is an adjunct instructor at Northeastern Illinois University College of Education.

1 thought on “A Case for Teaching with Cognates”

  1. Gonzalo Maldonado

    Insightful, objective study. Enjoyed reading about this and I can sense the passion behind the effort. Bi-lingual students can be supported and perhaps the use of two languages expands the linguistic parts of the brain leading to better learning.

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