Parents of young children are probably familiar with educator Roger Priddy’s infamous First 100 Words. The bestselling board book is a mainstay on baby registries and nursery bookshelves across the country. Now new research shows why that book and other resources designed to help children learn their first words may prove invaluable.

In a recent study published in Early Education and Development, researchers have found that children who enter preschool with good vocabulary and attention skills do better in class. The study, which involved 900 4-year-olds from eight U.S. states, asked them to identify common objects, such as fruit, zoo animals, and household items in pictures, and concluded that children with stronger vocabulary skills at the start of preschool “displayed more positive engagement with both their teachers and peers.”

“Children’s vocabulary skills rapidly grow and become increasingly complex in the preschool context; children both acquire and start to use more expressive vocabulary to communicate their needs and thoughts with others,” says lead author Qingqing Yang from the Ohio State University. “As part of this process, children learn more new words and abstract concepts and use those as psychological tools to represent and understand objective relations and social rules.”

Studies have shown that early vocabulary skills are a strong predictor for several academic outcomes, such as reading and math, as well as social and behavioral outcomes in later years.

Early academic success is part of the reason Brittany Bright, a Mississippi-based entrepreneur and content creator, started teaching her son, Jaxon, sight words shortly after his second birthday. Sight words are common words that kids are taught to recognize instantly–on sight–without sounding them out.

“We felt it was important because we knew that him learning sight words would help spark a love for reading,” says Bright, who reviewed sight words and numbers with Jaxon 10 to 15 minutes a day and documented his learning process through videos. “We’re so happy to see that even though he’s only just now starting kindergarten, he’s already thriving and breezing through the work.”

While there are no set criteria for the specific number of words children should know by preschool age, Yang points to the Early Learning Guidelines, which vary by state, for more information on which vocabulary skills preschoolers should have according to their age. For example, Ohio’s Early Learning and Development Standards suggest that children should be able to “use words acquired through conversations and shared reading experiences; identify real-life connections between words and their use; and explore relationships between word meanings, such as categories of objects, opposites, verbs describing similar actions—walk, march, prance, etc.”

In addition to picture books, Yang recommends interactive read-alouds, which provide opportunities for children to ask and answer questions about the text or picture instead of just listening to the story, as an effective way to help develop children’s vocabulary learning.

Beyond books, Yang suggests parents and caregivers have more conversations about the events children experience or the items they’re interested in. During these conversations, parents can repeat new words for children on different occasions to increase opportunities for children to hear and learn the words. Providing more details about new words, relating them to the child’s personal experiences, and explaining them using words the child is already familiar with is helpful as well.

“Accompanying words with actions, gestures, or facial expressions can also contribute to children’s understanding of the new words. It’s also important to wait and provide children with some time to respond using their own words,” says Yang. “Asking open-ended questions, such as ‘how’ and ‘why’ questions, can be a good way to elicit children’s responses. Parents and caregivers should pay attention to children’s interests based on their words and behaviors and use them as conversation starters.”