docs: fix grammar

docs/advanced/primitive.md

@@ -30,7 +30,7 @@ The `<primitive />` component is a versatile low-level component in TresJS that
 
 ## Usage with Models 
 
-The `<primitive />` component is is especially usefull to render complex objects like models loaded from external sources. The following example shows how to load a model from a GLTF file and render it using the `<primitive />` component.
+The `<primitive />` component is especially useful for rendering complex objects like models loaded from external sources. The following example shows how to load a model from a GLTF file and render it using the `<primitive />` component.
 
 ```html
 <script lang="ts" setup>