Even HSK Level 4 students still make mistakes with these, but that’s completely normal.
There is a simple way to remember them: “的” is followed by nouns, “地” is followed by verbs, and “得” is followed by complements.
Examples:
• 的: 漂亮的车 (the word after it is a noun)
• 地: 慢慢地走 (the word after it describes an action, a verb)
• 得: 开得很快 (the part after it describes degree or result, a complement)
In C-Tyme Chinese one-on-one lessons, all mistakes with “的 / 地 / 得” are corrected in every homework assignment. With 2–3 rounds of practice, most students can eliminate this mistake completely.