Some people really rate Grammarly - which you can plug into word.
I tried it and it did pick up on the many, many occasions where I'd missed out a comma, but at the same time it was extremely slow in a large document and I was writing a lot of dialogue in Scottish dialect which messed with it a bit.
I'd suggest finding a good beta reader if you can. You can highlight a few of the phrases you're worried about for them to cast an eye over. Or, bite the bullet and go for an editor. They might pick up on consistent problems with your style which would make you a better writer overall. It's just soooo expensive!