How to repair a grammar mistake that keeps returning
Reading the same rule again rarely fixes an automatic mistake. Repair needs contrast, retrieval and spaced reuse.
Name the exact pattern
Do not label the problem only as tense or preposition. Record the form you actually produce, such as I work here since two years.
Find the likely cause
Ask whether you transferred a pattern from another language, confused two English forms or simply could not retrieve the correct phrase under pressure.
Build a clear contrast
Place the attempt beside the correction and explain one decision only.
Not: I work here since two years. Correct: I have worked here for two years.
Reuse it in new contexts
Create three personal variations and say them aloud. Change the person, time and situation while keeping the repaired pattern.
Schedule a blind retest
Return after the correction is no longer fresh and answer without looking. If the error returns, shorten the prompt and practise the contrast again.