I hear this question time and time again from parents and professionals. Here are some resources that are helpful to me.
The child’s everyday life – I feel that this is the most important place to start. Are there concepts he/she is struggling with at home or school? Is there a special event coming up (like a special holiday, birthday party, wedding, etc.) that has specific vocabulary that could be targeted? And try not to just focus on nouns. It’s great if the child can label things, but can he/she put the doll under the table…or feed the carrots to the teddy bear…or go hide behind the door? I also like to work on categories, such as forks, knives, and spoons are utensils. Please see my article, Vocabulary Learning: A Lifelong Adventure , for more information.
Georgia Early Learning & Development Standards (GELDS) – http://www.gelds.decal.ga.gov/Search.aspx The “Communication, Language, and Literacy” and “Cognitive Development & General Knowledge” sections are extremely useful.
Georgia Standards of Excellence https://www.georgiastandards.org/Georgia-Standards/Pages/default.aspx This site breaks down the grade level standards for Kindergarten through 12th grade, and it can help target academic vocabulary. *This is specific to the state of Georgia so look for the standards in your state.
Spelling City – https://www.spellingcity.com/grade-level-lists.html Grade level word lists for a variety of subjects. I have found that many people underestimate the math concepts and vocabulary that are taught in the younger grades.
High Frequency Word Lists – This website that has several different high frequency word lists, such as Dolch, Fry, Marzano, etc. – https://www.readinga-z.com/high-frequency-words/
What resources are helpful to you? Please share, and I will add them to the list.