[russian] add information on questions

site-src/russian.wtn

@@ -88,4 +88,25 @@ etc.
 100|сто
 ===
 
+** Questions
+
+Yes/no-questions are made by just suffixing a statement with a question mark:
+
+===
+Do you want coffee? |Хотите кофе?
+===
+
+For other kinds of questions, you need to know the correct words:
+
+===
+what    |что    |What is this?                  |Что это?
+how     |как    |How do you pronounce this word?|Как вы произносите это слово?
+where   |где    |Where is my book?              |Где моя книга?
+when    |когда  |When did it happen?            |Когда это произошло?
+who     |кто    |Who are you?                   |Кто вы?
+how many|сколько|How many were there?           |Сколько их было?
+===
+
+'Which' is often expressed using the adjective 'какой', as in "какой этаж?" (which floor?)
+
 {toska тоска}