Basic C++ problems

That's not how you do an or.
Must write

Code:

if (ch == '?' || ch == '.' || ch == ';' || ch == ':' || ch == '!')

or, even clearer

Code:

if ((ch == '?') || (ch == '.') || (ch == ';') || (ch == ':') || (ch == '!'))

C is quirky in that the way you wrote it compiles without warning, but it does not do what you think it does.

Also, in your loop, you advance i, but do not recompute ch.