diff --git a/Tp09/merge_sort.py b/Tp09/merge_sort.py
index 211389d2ed13b0eea43838460eb347975b103d3f..23d33ac58c18408dd150538991aeb9e8f4b86ed5 100755
--- a/Tp09/merge_sort.py
+++ b/Tp09/merge_sort.py
@@ -57,7 +57,7 @@ def length(li: ApLst) -> int:
     3
     """
     if not li.is_empty():
-        res = 1 + lenght(li.tail())
+        res = 1 + length(li.tail())
     else:
         res = 0
     return res
@@ -85,7 +85,11 @@ def native_to_list(li: list[T]) -> ApLst:
     $$$ l.head()
     4
     """
-    
+    if li != []:
+        res = ApLst(li[0], native_to_list(li[1:]))
+    else:
+        res = ApLst()
+    return res
 
 
 def list_to_native(li: ApLst) -> list[T]: