[danik.js]

var string = "Сидел в траве кузнечик.Совсем как огуречик зелёненький.";
var sentences = [];
var dotIndex = -1;
do {
	var startIndex = dotIndex + 1;
	dotIndex = string.indexOf('.', startIndex);
	var endIndex = dotIndex > -1 ? dotIndex : Infinity;
	var sentence = string.substring(startIndex, endIndex);
        if (sentence)
	    sentences.push(sentence);
} while (dotIndex > -1);

var result = [];
for (var i = 0; i < sentences.length; i++) {
	var words = sentences[i].split(' ');
	result.push(words.slice(0, -2));
}
alert(result);