Index: gc_core/py/lang_core/gc_engine.py
==================================================================
--- gc_core/py/lang_core/gc_engine.py
+++ gc_core/py/lang_core/gc_engine.py
@@ -990,16 +990,21 @@
 
 
 
 #### Analyse tokens
 
-def g_morph (dToken, sPattern, sNegPattern=""):
+def g_morph (dToken, sPattern, sNegPattern="", nLeft=None, nRight=None, bMemorizeMorph=True):
     "analyse a token, return True if <sNegPattern> not in morphologies and <sPattern> in morphologies"
     if "lMorph" in dToken:
         lMorph = dToken["lMorph"]
     else:
-        lMorph = _oSpellChecker.getMorph(dToken["sValue"])
+        if nLeft is not None:
+            lMorph = _oSpellChecker.getMorph(dToken["sValue"][slice(nLeft, nRight)])
+            if bMemorizeMorph:
+                dToken["lMorph"] = lMorph
+        else:
+            lMorph = _oSpellChecker.getMorph(dToken["sValue"])
         if not lMorph:
             return False
     # check negative condition
     if sNegPattern:
         if sNegPattern == "*":
@@ -1013,13 +1018,14 @@
     # search sPattern
     zPattern = re.compile(sPattern)
     return any(zPattern.search(sMorph)  for sMorph in lMorph)
 
 
-def g_analyse (dToken, sPattern, sNegPattern=""):
+def g_analyse (dToken, sPattern, sNegPattern="", nLeft=None, nRight=None, bMemorizeMorph=True):
     "analyse a token, return True if <sNegPattern> not in morphologies and <sPattern> in morphologies (disambiguation off)"
-    lMorph = _oSpellChecker.getMorph(dToken["sValue"])
+    sValue = dToken["sValue"]  if nLeft is not None  else dToken["sValue"][slice(nLeft, nRight)]
+    lMorph = _oSpellChecker.getMorph(sValue)
     if not lMorph:
         return False
     # check negative condition
     if sNegPattern:
         if sNegPattern == "*":