For French native speakers, English as a second language must be relatively EASIER to learn compared to the effort needed by Japanese native speakers.
I wonder whether there is a study to rank the effort level needed for non-English native speakers to learn English as a second language?
For example, in a 10-point ranking, maybe for French speakers the effort level is 3 while for Japanese speakers the effort level is 8?
It would be nice to also know the reasons why learning English as a second language is hard for native speakers of non-English languages.
I hope this question is acceptable at least on the meta site, if not for the main site. Otherwise, please let me know how to update this question for this site, or whether another site is more appropriate.