Commas and clauses
My experience of reading junior engineers' English was of seeing clause after clause separated by commas, with only the occasional full stop. No other type of punctuation mark.
It was English written as it is spoken, but often with very limited vocabulary. No concept that writing is a more formal performance.
One of them told me once that I was the first person who had ever gone through their writing to point out the mistakes. This from a person in their early twenties.