My favorite (evidence backed) theory on how humans learn is Retrieval Practice.
https://www.learningscientists.org/blog/2024/3/7/how-does-retrieval-improve-new-learning

Humans don’t really learn when we download info into our brain, we learn when we expend effort to pull that info out. This has some big implications for designing collaborative tooling!

The “thing” that we learn most effectively is not knowledge as we typically think of it, it’s process. This should be intuitive, if we put into a bit of a more natural context. Imaging learning baking for a moment: Do you teach someone to bake a cake by spitting out a fact sheet of ingredients and having them memorize it? Or do you teach them the process?

Reading and listening are two fundamentally different modes of learning. Reading is a standalone activity, but it tends to create stronger memories because your brain needs to fill in many gaps that listening pre-populates. What does the setting look like? What do the voices sound like? Reading uses back-tracking eye movements to maximize retention. Turning pages is a built-in break, giving you time to process what you’ve read. Reading also provides structural cues from punctuation, and physical books give you a spatial sense of where you are in the story at all times, both of which help improve your memory.

Listening, on the other hand, is a more social experience. You can glean information from one’s intonation, volume, and speed. Because you can’t rewind a conversation, you tend to focus on extracting the most important points. Listeners thrive on interaction and spontaneity. They love hearing multiple angles until one clicks, and that’s when the words magically roll off their tongue in response.

The biggest difference between the two is that listening still works when you do it passively — you can let the information run over you like a waterfall, and your subconscious will save the most relevant bits as they pass by — while reading requires constant attention. It is entirely active, like a treasure hunt.

https://web.archive.org/web/20070228193210/http://www.mindtools.com/pages/article/newTIM_10.htm

3. The hundred most common words
   Tony Buzan, in his book 'Using your Memory', points out that just 100 words comprise 50% of all words used in conversation in a language. Learning this core 100 words gets you a long way towards being able to speak in that language, albeit at a basic level. The 100 basic words used in conversation are shown below:

4. A,an 2. After 3. Again 4. All 5. Almost

5. Also 7. Always 8. And 9. Because 10. Before

6. Big 12. But 13. (I) can 14. (I) come 15. Either/or

7. (I) find 17. First 18. For 19. Friend 20. From

8. (I) go 22. Good 23. Good-bye 24. Happy 25. (I) have

9. He 27. Hello 28. Here 29. How 30. I

10. (I) am 32. If 33. In 34. (I) know 35. Last

11. (I) like 37. Little 38. (I) love 39. (I) make 40. Many

12. One 42. More 43. Most 44. Much 45. My

13. New 47. No 48. Not 49. Now 50. Of

14. Often 52. On 53. One 54. Only 55. Or

15. Other 57. Our 58. Out 59. Over 60. People

16. Place 62. Please 63. Same 64. (I) see 65. She

17. So 67. Some 68. Sometimes 69. Still 70. Such

18. (I) tell 72. Thank you 73. That 74. The 75. Their

19. Them 77. Then 78. There is 79. They 80. Thing

20. (I) think 82. This 83. Time 84. To 85. Under

21. Up 87. Us 88. (I) use 89. Very 90. We

22. What 92. When 93. Where 94. Which 95. Who

23. Why 97. With 98. Yes 99. You 100. Your
    (Extract reproduced from Use Your Memory by Tony Buzan with the permission of BBC Worldwide Limited, © Tony Buzan)