There are many parameters. For instance, the syntax of English language is S-V-O. However, in Turkish language it is S-O-V. There are a lot of suffixes that a person can add in Turkish language but there is not a single prefix, infix etc. On the other hand, English language has lots of prefixes. As a result, it results in confusing for language learners. At least, English language doesn't have any circumfixes or infixes, it could be even more challenging for Turkish language learners if it had. On the other side, education system of Turkey doesn't provide a good amount of language teaching. I even suspect most of the English Language Teachers in Turkey really knows how to speak English. Also, most of the teachers are just preparing students for exams such as YDS, YDT.