The phrase 'get behind with' is a correct and usable phrase in written English.
You can use it to describe the situation when someone is not keeping up with the progress that is expected or required. For example, "The student got behind with his school work, so he had to work extra hard to finish his assignments on time."
When choosing which channels to get behind with marketing, the cable companies act accordingly.
You either spend time dealing with emails, which leaves less time for preparing lessons and marking, or do a chunk of marking and get behind with your emails.
When my kids began to grow out of them, I was thrilled to come across Disney's "Phineas and Ferb," an even more sophisticated procedural, and one whose values I could get behind, with its utopian, throwback vision of a childhood free of endless adult oversight.
What we need is a roadmap for preventing chronic disease that the entire nation can get behind – with the three-part goal of improving the well-being of all Americans, avoiding unnecessary costs and suffering, and building on existing initiatives and infrastructure.
Simply getting behind with the rent is not enough.
If there's any danger of getting behind with the mortgage, talk to your lender as soon as possible rather than putting it off.
He got behind with the work and didn't like to ask questions in front of people who were a lot cleverer than him.
He told the police that he had gotten behind with deliveries because of night school studies and felt too overtaxed to catch up.
If he got behind with his chores, his mother forced him to swallow spoonfuls of ammonia or locked him in the bathroom to inhale the rasping fumes from a bucket of ammonia and bleach.
"Once he crosses the line from getting behind with payments or something into total premeditated fraud, he must have planned his leaving.
And he has revealed enough evangelical ability at the end of the journey for the party to get behind him with more relish than it had previously shown.
