diff --git a/num2words/__init__.py b/num2words/__init__.py
index 69ad8db..a53456a 100644
--- a/num2words/__init__.py
+++ b/num2words/__init__.py
@@ -63,7 +63,10 @@ CONVERTER_CLASSES = {
     'vi_VN': lang_VN.Num2Word_VN()
 }
 
-def num2words(number, ordinal=False, lang='en'):
+CONVERTES_TYPES = ['cardinal', 'ordinal', 'year', 'currency']
+
+
+def num2words(number, ordinal=False, lang='en', to='cardinal'):
     # We try the full language first
     if lang not in CONVERTER_CLASSES:
         # ... and then try only the first 2 letters
@@ -71,7 +74,11 @@ def num2words(number, ordinal=False, lang='en'):
     if lang not in CONVERTER_CLASSES:
         raise NotImplementedError()
     converter = CONVERTER_CLASSES[lang]
+    # backwards compatible
     if ordinal:
         return converter.to_ordinal(number)
-    else:
-        return converter.to_cardinal(number)
+
+    if to not in CONVERTES_TYPES:
+        raise NotImplementedError()
+
+    return getattr(converter, 'to_{}'.format(to))(number)