Declared the methods and copied the XMLDoc from the readme.adoc file to each method

VocabularyTrainer/VocabularyItem.cs

@@ -5,5 +5,63 @@
 /// </summary>
 public sealed class VocabularyItem
 {
-    // TODO
+    private int _countCorrect;
+    private int _countAsked;
+    public readonly string NativeWord;
+    public readonly string Translation;
+
+    VocabularyItem(string nativeWord, string translation)
+    {
+        NativeWord = nativeWord;
+        Translation = translation;
+    }
+    
+    /// <summary>
+    ///     A translation attempt is checked for correctness.
+    /// </summary>
+    /// <param name="translationAttempt">The user provided translation</param>
+    /// <returns>True if the translation was correct; false otherwise</returns>
+    public bool TestTranslation(string translationAttempt)
+    {
+        _countAsked++;
+        if (Translation == translationAttempt)
+        {
+            _countCorrect++;
+            return true;
+        }
+
+        return false;
+    }
+    
+    /// <summary>
+    ///     The vocabulary item is compared to another. First the number of correct answers is compared.
+    ///     If it is equal the native words are compared ordinal.
+    /// </summary>
+    /// <param name="other">The <see cref="VocabularyItem"/> to compare with</param>
+    /// <returns>0 if equal; less than 0 if this item is smaller; greater than 0 otherwise</returns>
+    public int CompareTo(VocabularyItem other)
+    {
+        return -1;
+    }
+    
+    /// <summary>
+    ///     Overrides the default string representation to display the word and translation statistics.
+    /// </summary>
+    /// <returns>A string containing the word, its translation and the training statistics</returns>
+    public override string ToString()
+    {
+        return string.Empty;
+    }
+    
+    /// <summary>
+    ///     Compares two strings by ordinal value, ignoring case.
+    /// </summary>
+    /// <param name="a">First string</param>
+    /// <param name="b">Second string</param>
+    /// <returns>Less than 0 if a precedes b in the sorting order; greater than 0 if b precedes a; 0 otherwise</returns>
+
+    private static int CompareStrings(string a, string b)
+    {
+        return -1;
+    }
 }