I thought my grammar was okay but...

I just received a good review on Amazon for The Fall. They gave me 4 stars, which is excellent, but they also gave me a few nuggets to help me as well. I've always thought my grammar has been quite good so far but apparently not, so I'm taking this advice to heart and having another look through The Fall one sentence at a time. The reviewer was right. There are a few grammar errors here and there; some I can sort out, some I'm not altogether sure about. While the review annoyed me at first (how dare I be criticised like this!) I've found what they wrote to be invaluable to my career as a writer. They took the time to point out some of my mistakes and that can only be a good thing. Hopefully this means I can write a better sequel.