First u can take 2 list of Strings Var a =new List<string>(){"API","UI"} ; var b=new List<string> (){"Application Programming Interface","User Interface"} ; Result: ===== API = Application Programming Interface UI = User Interface Firs you can create on extension method for this public static class ExtentionMethod { public static void YDR<T>(this IEnumerable dr,Action<T,int> y) { int initials = 0; foreach (T item in dr) { y(item,initials ++); } } } public static Dictionary<TKey,TValue> Adding<TKey, TValue>(IEnumerable<TKey> keys,IEnumerable<TValue> values) { var dictonary = new Dictionary<TKey,TValue>(); keys.YDR<TKey>((x,i) => { dictonary .Add(x,values.ElementAt(i)); }); return dictonary; } Use case : ======= Create a class and use this method public Dictionary<...