If you look at the research on vocabulary acquisition, you’ll find a surprising result: weirdly enough, learning groups of similar words (apple, pear, banana) is significantly harder to learn. You’ll be much better off if you either learn words in unrelated groups (apple, dog, red) or in groups that form stories (apple, sweet, to eat). — Interesting article discussing the research on efficient ways of learning vocabulary. In short - chain words together to learn them - not group them in categories. Be aware though - this doesn’t neccessarily mean categorising them in a AAC system is a bad idea - its just questioning how we learn the words. See here for the full article.