My web contain many forum and i have change many forum it just little change by omitting little words,,,my question is this changing make error in google search result or its ok no proble?? and will google bot will recrawling any changing of my forum???
thankss
In my experience, making small changes here and there will have little affect on your SE ranking. What you're doing, on page optimization, should be part of a broader SEO strategy. You'll find better results balancing on page and off page optimization.
To answer your second question: Google will re-crawl if it deems fit.
You have to learn how to redirect 301.