Section outline

      1. Native speakers of English are usually more irritated when English is spoken badly by other native speakers than by non-native speakers. Moreover, people are willing to forgive a lot from a person who does not speak English well if he or she explains in the beginning that they are not a native speaker.
      2. On the other hand, native speakers of English will be annoyed by people who cannot speak English properly in their professional capacity. They will also expect written English to be grammatically correct, with appropriate vocabulary and tone.
      3. You can always use text checkers online, for example Paper Rater, to improve the language of your presentation.