(cambodian): Learn Khmer
If you are physically in Cambodia, immersion is your best friend.
The script is beautiful but complex. It has 33 consonants and 24 vowels (plus additional "personal" vowels), which can be daunting for beginners. Learn Khmer (Cambodian)
Reaching an advanced level where you can discuss complex ideas typically takes 1 to 2 years of consistent practice. Top Ways to Learn If you are physically in Cambodia, immersion is