Successfully Using English at Work. Tip #4: Don’t Be Shy or Embarrassed, Just Do Your Best
In the end, the most important thing is to just try your best. Don’t worry about the little errors when speaking to co-workers. The most important thing is to be understood—even if you accidentally (нечаянно) use the wrong tense or say something strange.
As a non-native speaker, you will make mistakes, and that’s okay. Your boss and co-workers know that, and they should be helpful (готовый помочь). If they aren’t, maybe you’re in the wrong workplace. Best of luck!