The attorney who prepared the application you are now prosecuting was not very good at grammar or spelling. You want to file a preliminary amendment cleaning up the specification, without of course adding any of that dread new matter. Can you do that and, if so, how?

It’s easy. It used to be the case that you could file a substitute specification only when the examiner required one. You may see that on old exam questions so make a mental note that such is Kaput.
Today, 37 CFR 1.125, MPEP 608.01(q) lets you file a substitute or rewritten specification whenever your little heart desires. The examiner still can require a new specification as well. You can do this up until payment of the issue fee, after which a new spec might interfere with issuance and your Office will not tolerate that.
You do have to include a statement that you haven’t snuck any new matter into the new spec.