Learn Dutch: Sommige mensen kalmeren zodra we er zakelijk mee doorgaan. - Some people calm down as soon as we proceed with it professionally.

In Dutch, pronominal adverbs like ermee (with it) are often split. In a subordinate clause, the er part usually comes right after the subject (we), while the preposition part (mee) moves toward the end, just before the verbs. Other adverbs, like zakelijk (professionally), are sandwiched between them.

Why is doorgaan written as one word at the end, instead of splitting into door and gaan?

doorgaan (to continue or proceed) is a separable verb. However, separable verbs only split when they are the conjugated verb in a main clause. Because zodra (as soon as) creates a subordinate clause, the verb is pushed to the end. When a separable verb is pushed to the end of a clause, its prefix and verb glue back together into a single word.

Is zakelijk an adjective or an adverb here?

It acts as an adverb here, describing how we proceed (doorgaan). In Dutch, adjectives and adverbs usually share the exact same form, so zakelijk can mean both professional (adjective) and professionally (adverb).

Can I keep ermee together and place it somewhere else in the subclause?

You can technically keep it together right after the subject, like zodra we ermee zakelijk doorgaan, but splitting it is much more natural and common in Dutch. However, you can never place ermee at the very end of the sentence after the verbs.