Chantelle Ferguson (firstname.lastname@example.org), Director of Online Language Support, offered her perspective and suggestions for instructors whose native language is not English:
Communicating in a second (or a third…) language can be challenging for even the most proficient of speakers. Because English has developed independently in many parts of the world, there is no guarantee that two English speakers will understand one another all of the time. Common expressions learned in Australia might be a mystery to those who learned English in Jamaica. Likewise, an accent perfected in Ireland might be difficult to understand for those who learned English in the United States or Japan.
Fortunately, it is human nature to want to understand others and to be understood. This is especially true in educational settings where teachers want to teach and students want to learn—even though English may be a non-native language to both. Because teachers often repeat information in lectures and demonstrations, in feedback on student work, and in answers to questions, they can use strategies focused on these crucial teacher-student interactions to become more effective communicators.
See Chantelle's strategies for Teaching in a Non-Native Language, including suggestions for both online and onsite instructors.