I know core tenses isn't as sexy as business expressions but it is arguably much more important. Making mistakes with core tenses (present, past, future, present perfect) is a more serious mistake than for example missing an S on your plural or using an ininstead of an on preposition. I spend a lot of my time working with my students on these core tenses so that there are perfect. If you have a great command of these core tenses you can be confident working in a business environment in English.
Remember that the first step is to be aware that you're making a mistake and then you can correct it. A coach should identify your mistakes and help you along the way to improving them.
ANNA WITH 2NS PODCAST - Business English every Wednesday