, чтобы отделить два первых предложения, это должно сделать это быстро:
$str = "Lorem Ipsum dolor sit amet etc etc. Blabla 2. Blabla 3. Test 4.";
$p1 = "";
$p2 = "";
explode_paragraph($str, $p1, $p2); // fills $p1 and $p2
echo $p1; // two first sentences
echo $p2; // the rest of the paragraph
function explode_paragraph($str, &$part1, &$part2) {
$s = $str;
$first = strpos($s,"."); // tries to find the first dot
if ($first>-1) {
$s = substr($s, $first); // crop the paragraph after the first dot
$second = strpos($s,"."); // tries to find the second dot
if ($second>-1) { // a second one ?
$part1 = substr($str, 9, $second); //
$part2 = substr($str, $second);
} else { // only one dot : part1 will be everything, no part2
$part1 = $str;
$part2 = "";
}
} else { // no sentences at all.. put something in part1 ?
$part1 = ""; // $part1 = $str;
$part2 = "";
}
}