2. Are you perfect in your native language? You should know: Nobody is perfect! In all language areas you can register different personal  vocabularies and expression schemes – often regionally or professionally influenced. Between German speaking areas of Germany (and its different regions), Austria and Switzerland there sometimes are substantial differences. And even remembering my former teachers, lecturers and collegues at university – all „academics“ - and my friends with different professions, they didn´t speak and write respectively don´t same way, but they all have been or are native speakers, more or less perfect. Well educated people mostly have large vocabularies often using synonyms. Other people often don´t know certain synonyms and may think: Is that good German? It´s not easy to evaluate if language proficency is perfect or not, specially not for a not native speaker.