Word Learning in Bilingual Typical and Late Talking Children: The Role of Meaning and Input

Dual Language Input, Semantic Structure and Word Learning in Typically Developing and Late Talking Bilingual Children

The goal of this clinical trial is to understand how different types of word categories, along with the language children hear from their parents, support bilingual toddlers' word learning. This study will address two main questions: (1) How are the words toddlers know related to the words their parents use? and (2) How does what toddlers already know help them learn new words in two languages? The investigators will compare bilingual toddlers with typical development to those with language delay to determine whether they learn new words in similar ways.

Children's vocabulary knowledge will be assessed using standardized parent-report checklists. To examine how different types of categories support learning, the study will focus on two early-acquired categories: animals and clothing. The investigators will compare what parents report about their children's vocabulary with how children learn new words within each category.

To understand the role of parent input, children and their parents will engage in shared book reading and play activities using materials from one of the target categories. Parent-child interactions will be video recorded. Children will also complete an eye-tracking task in which they learn new words in two languages within the same category.

Study Overview

• Status: Recruiting
• Conditions: Bilingualism; Vocabulary Acquisition; Late Talkers; Network Science
• Intervention / Treatment: Behavioral: Large Semantic Category Condition; Behavioral: Small Semantic Category Condition

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Recruiting
      • Boston University
      • Contact: Kimberly Crespo, PhD, CCC-SLP; Phone Number: (617) 358-0790; Email: kcrespo@bu.edu
      • Principal Investigator: Kimberly Crespo, PhD, CCC-SLP

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• At least 10% exposure to both English and Spanish or at least 90% exposure to English and another language

Exclusion Criteria:

• Hearing impairment
• Uncorrected visual impairment
• Neurological impairment
• Genetic syndromes
• Neurodevelopmental disabilities (e.g. autism)
• More than 10% exposure to a language other than English or Spanish

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Toddlers with typical language development; Children who have typical vocabulary sizes and do not have a history of hearing or vision impairment, neurodevelopmental disorders, or neurological or cognitive delays/disorders.	Behavioral: Large Semantic Category Condition; Participants will learn new words that refer to objects that belong to a category from which toddlers know many words (i.e., animals). They will learn new animal words in two different language conditions: a single language context and a dual language context. In the single language context, they will learn new English-like words in a learning environment where they only hear one language (i.e., English). In the dual language context, they will learn new English-like and Spanish-like words in a learning environment where they only hear both languages. Participants and their parents will also read books about animals and play with animal toy sets.; Behavioral: Small Semantic Category Condition; Participants will learn new words that refer to objects that belong to a category from which toddlers know few words (i.e., clothing). They will learn new clothing words in two different language conditions: a single language context and a dual language context. In the single language context, they will learn new English-like words in a learning environment where they only hear one language (i.e., English). In the dual language context, they will learn new English-like and Spanish-like words in a learning environment where they only hear both languages. Participants and their parents will also read books about clothes and play with toy sets that include clothing.
Experimental: Toddlers with language delay; Children whose vocabulary size is atypically small for their age in the absence of hearing impairment, neurodevelopmental disorders, or other cognitive delays.	Behavioral: Large Semantic Category Condition; Participants will learn new words that refer to objects that belong to a category from which toddlers know many words (i.e., animals). They will learn new animal words in two different language conditions: a single language context and a dual language context. In the single language context, they will learn new English-like words in a learning environment where they only hear one language (i.e., English). In the dual language context, they will learn new English-like and Spanish-like words in a learning environment where they only hear both languages. Participants and their parents will also read books about animals and play with animal toy sets.; Behavioral: Small Semantic Category Condition; Participants will learn new words that refer to objects that belong to a category from which toddlers know few words (i.e., clothing). They will learn new clothing words in two different language conditions: a single language context and a dual language context. In the single language context, they will learn new English-like words in a learning environment where they only hear one language (i.e., English). In the dual language context, they will learn new English-like and Spanish-like words in a learning environment where they only hear both languages. Participants and their parents will also read books about clothes and play with toy sets that include clothing.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Word learning	The researchers will assess learning through participants' looking behavior via experimental eye-tracking paradigms. Specifically, the researchers will measure how accurately and quickly participants look to the target object after hearing its name.	Day 1
Vocabulary Network Properties	The researchers will characterize participants' vocabulary size and structure using the MacArthur-Bates Communicative Development Inventories (MB-CDI). Vocabulary size will be calculated using the raw number of words produced (range: 0-680 words) and their age-matched percentile score from the MB-CDI (range: 0-100). Higher scores indicate larger vocabulary sizes.The researchers will also calculate how many words each participant knows in in two categories on the MB-CDI (i.e., animals [0-43 words] and tools [0-28 words]) across the languages they are learning (i.e., English and Spanish). Network properties may include the number of words in a category and the number of connections between words in a category.	Day 1
Parent Language Input	The researchers will calculate the number of words the parent says to their child during book reading and toy play activities. Language input will be defined as the total number of nouns and verbs (tokens) and the number of unique nouns and verbs (types).	Day 1

Collaborators and Investigators

• Sponsor: Boston University Charles River Campus
• Collaborators: National Institute on Deafness and Other Communication Disorders (NIDCD)

Study record dates

Study Major Dates

• Study Start (Actual): December 16, 2025
• Primary Completion (Estimated): July 31, 2028
• Study Completion (Estimated): July 31, 2029

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 19, 2026
• First Posted (Actual): May 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 19, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: toddlers; vocabulary; late talkers; bilingualism; word learning; parent input
• Other Study ID Numbers: K23DC022006 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No