How do I understand non-native English speakers with heavy accents better?

Answer 1

I think the best way is through exposure. The more you hear (and negotiate meaning with bilinguals who demonstrate) the heavily-accented English, the better you become at identifying the pronunciation characteristics that make recognizing what is being said easier. If you are familiar with the speaker's first language and how it might influence their pronunciation of English, that can help as well (for example, a Japanese speaker's difficulty distinguishing /l/ from /r/ or a Portuguese speaker's tendency to add a vowel sound before words beginning with /s/) because it gives you a sense of what to expect. However these features can be more overarching than individual sounds (i.e., is the rhythm & stress of their first language very different from English) and therefore very difficult to "learn" how to understand them more efficiently. Try your best to be patient and a sympathetic listener, and hopefully the effort needed to understand folks with heavy accents improves.