You'd probably want to match anything (.*?) followed by the end of sentence followed by whitespace (\s+). Since !, ? and . are special characters, you'll need to excape them.
eg
Pattern pattern = Pattern.compile("(.*?)[\\!\\?\\.]\\s+");
Matcher matcher = pattern.matcher("one two. three! four five? ");
while (matcher.find()) {
System.out.println(matcher.group(1));
}
prints
one two
three
four five