Deciding whether to start a third language or continue studying L2 can be completely opinion-based. Some people think English is enough but others don't. But there are always people (For example myself) who always dream of being getting fluent in a third language but don't know whether it's the time to start or not.
I've seen this question and I know there may be disadvantages and also advantages and you shouldn't quit L2 let your it get passive in your mind while learning L3.
But my question is
- Are there any criteria to ensure me that I am proficient enough in English to start another language? (Suppose that English is the most important)
- What factors should I consider in my decision when choosing the right time to start?
In fact I'm searching for any statistical evidence, standard , etc to help me decide easier for an opinion-based problem