using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<string> words = new List<string> { "Mode", "Model", "Model:" };

        string Text = "This is Model: x Type: Model: y aa: Mode e";

​

        var splitted = Text.Split(' ');

        var items = words.Select(x => new { Word = x, Count = splitted.Count(y => y == x) });

        foreach(var item in items)

        {

            Console.WriteLine("{0} -> {1}", item.Word, item.Count);

        }

    }

}