diff -r ae159980e4ef -r 0d915578ce19 www/en-affixes.rst
--- a/www/en-affixes.rst	Tue Dec 06 00:09:42 2016 +0200
+++ b/www/en-affixes.rst	Tue Dec 06 23:53:33 2016 +0200
@@ -23,6 +23,22 @@
 
   memos, photos, pianos, videos
 
+``fe`` changed to ``ve`` and ``s`` append::
+
+  knife ⇒ knives, life ⇒ lives, wife ⇒ wives
+
+``f`` changed to ``v`` and ``es`` append::
+
+  half ⇒ halves, wolf ⇒ wolves, loaf ⇒ loaves
+
+``us`` changes to ``i``::
+
+  cactus ⇒ cacti, nucleus ⇒ nuclei, focus ⇒ foci
+
+``is`` changed to ``es``::
+
+  analysis ⇒ analyses, crisis ⇒ crises, thesis ⇒ theses 
+
 Words ending in consonant + ``-y`` change ``-y`` to ``-i`` and ``-es`` is
 appended::