Duolingo may assist you in gaining a foundational understanding of a number of languages, but it is restricted in what it teaches and how difficult it makes you work. Your reading, writing, listening, and speaking abilities will probably need to be improved, depending on your objectives and past knowledge.
Duolingo English test validity
The Duolingo English Test certificate has a two-year validity period once you obtain your score, just like any other certificate. The sole restriction is that you must repeat the test within this window to show that your English language proficiency has improved. Though English is not your first language, you might need to repeat the exam even if you have lived in the US for a long time. The validity of the Duolingo English test will also vary based on a number of variables, including how much you prepared for the exam, how your English has improved since then, and if you can pass the test if you retake it.