It might be an odd question but how to handle bad English By handle I mean: understand it and correct it. Sometimes you meet phrases that are written in very bad English. Mostly the work of poor translators. When you read these articles you can't surely know if what you've understood is what is really written. You always have to guess. There are many examples on the web.
Remember the person who writes poor English might be a literary genius in their native language. Second languages can be hard, especially if you're not regularly exposed to native speakers.
There is always a logic behind every sentence, no matter how poorly formed. If you are familiar with the quirks of a particular language, you can sometimes guess what the native speaker of that language is trying to say in English, just filtered through what is familiar to them.
English is a notoriously difficult language. It has many common quirks that make no logical sense and which must be memorized. It contradicts itself all over the place, and nuances vary widely from dialect to dialect.
Perhaps more than any other language, English speakers get used to non-native speakers trying to communicate in English and (hopefully) learn to "read between the lines" when something is unclear. Of course there are many people who won't bother, but as someone who has been in the same situation in many other countries where I didn't speak the native language, I try to empathize with what anyone is trying to say.