Writers do not make random errors — they make the same three or four errors over and over. So do not proofread for “grammar.” Proofread for your grammar, one pattern at a time. Run each pass over this draft, decide whether every flagged word is actually wrong, then sort the real rules from the superstitions and build the inventory that replaces the handbook.
Verdict
StartChoose a pass on the left. Each one looks for a single pattern — that is the entire reason they work.