You might be proficient with your second language skills, yet that does not mean you can actually stand in front of a group and pass on your knowledge.
My spoken English is rusty and sadly I’ve lost the cocky British accent that the British School taught me, and that is a blessing. Writing in English with eloquent phrases is certainly an advantage, however doing so while standing in front of a restless and nervous group will result in a terrible academic experience.
Grads and undergraduates are asked to speak and write in English, and so they do it. Nonetheless, it is not the same to gain the basic communication skills than to learn from an equally nervous professor.
This I would call challenge number one. The professor is more worried about his pronunciation and therefore troubled that the class would not understand, so he spends most of his time translating instead of actually teaching. In my experience this is easily solved with two main activities. The first one is to find analogies and synonyms for the concepts to be taught and learn them by heart, and the second one is to keep the language and ideas as simple as possible. So an impecable accent is actually not required.
The second challenge is to have the students focused on the topic and captive in class. If keeping them tuned in a session in their native tongue is difficult, in English is even a bigger venture. What I have learnt to overcome this issue is to actually change the game. The professor is there to guide knowledge, and yes, sometimes to lecture, but a good alternative to break the monologue is to transfer some responsibility to the learners.
When a student is given some authority to do, explain, and train colleagues, the teaching method evolves from memorizing something to actually absorb the knowledge. Professor Feynman said this better: “If you want to master something, teach it”.
Which leads me to the third impasse. Students rely too much on the impact they leave on their classmates, so not knowing a word, misspelling it, or have a bad articulation limits their class participation. To confront this matter I’ve settled a couple of ground rules that most participants identify to.
On the one hand, it is rare to have a native speaker student and for that reason none are fluent talkers, nor they have excellent English skills, so everyone’s allowed to make mistakes, even the professor, without being mocked. On the other hand, all assistants are bound to participate and express their thoughts and ideas in English despite their accent and probable flaws.
In my experience, these are the main concerns of lecturing in another language. So, in order to conquer them, you basically need talk in a simple manner about your subject to build on your learning skills. Then risk it and give your students the opportunity to prove their understanding of a certain concept or scheme with the certainty that no one will scoff about their exposition. Thus you will enhance the teaching experience giving your attendants the possibility to master another language, increase personal confidence, and of course, your subject’s theme.