diff --git a/src/dutch/CatDut.gf b/src/dutch/CatDut.gf
index 09ae24dfd..b6d8bab62 100644
--- a/src/dutch/CatDut.gf
+++ b/src/dutch/CatDut.gf
@@ -21,10 +21,10 @@ concrete CatDut of Cat =
 -- Question
 
     QCl = {s : ResDut.Tense => Anteriority => Polarity => QForm => Str} ;
-    IP = {s : NPCase => Str ; n : Number} ;
+    IP = MergesWithPrep ** {s : NPCase => Str ; n : Number} ; -- met wat -> waarmee
     IComp  = {s : Agr => Str} ; 
-    IDet   = {s : Gender => Str ; n : Number} ;
-    IQuant = {s : Number => Gender => Str} ;
+    IDet   = MergesWithPrep ** {s : Gender => Str ; n : Number} ;
+    IQuant = MergesWithPrep ** {s : Number => Gender => Str} ;
 
 -- Relative
 
diff --git a/src/dutch/QuestionDut.gf b/src/dutch/QuestionDut.gf
index 802dde0c5..9468c7fb7 100644
--- a/src/dutch/QuestionDut.gf
+++ b/src/dutch/QuestionDut.gf
@@ -60,19 +60,18 @@ concrete QuestionDut of Question = CatDut ** open ResDut in {
       } ;
 
     PrepIP p ip = {
-      s = appPrep p (noMerge ** ip)
+      s = appPrep p ip
       } ;
 
-    AdvIP ip adv = {
+    AdvIP ip adv = ip ** {
       s = \\c => ip.s ! c ++ adv.s ;
-      n = ip.n
       } ;
 
     IdetCN idet cn = 
       let 
         g = cn.g ;
         n = idet.n
-      in {
+      in noMerge ** {
       s = \\c => idet.s ! g ++ cn.s ! Weak ! NF n Nom ; 
       n = n
       } ;
@@ -83,7 +82,9 @@ concrete QuestionDut of Question = CatDut ** open ResDut in {
         n = idet.n
       in {
         s = \\_ => idet.s ! g ;
-        n = n
+        n = n ;
+        mergesWithPrep = idet.mergesWithPrep ;
+        mergeForm = idet.mergeForm
       } ;
 
     IdetQuant idet num = 
@@ -91,7 +92,9 @@ concrete QuestionDut of Question = CatDut ** open ResDut in {
         n = num.n
       in {
       s = \\g => idet.s ! n ! g ++ num.s  ; 
-      n = n
+      n = n ;
+      mergesWithPrep = idet.mergesWithPrep ;
+      mergeForm = idet.mergeForm
       } ;
 
     AdvIAdv i a = {s = i.s ++ a.s} ;
diff --git a/src/dutch/StructuralDut.gf b/src/dutch/StructuralDut.gf
index 713b18472..a25c34f8e 100644
--- a/src/dutch/StructuralDut.gf
+++ b/src/dutch/StructuralDut.gf
@@ -44,7 +44,8 @@ concrete StructuralDut of Structural = CatDut, Prelude **
   in8front_Prep = mkPrep "voor" ;
   i_Pron = mkPronoun "ik" "me" "mijn" "ik" "mij" "mijn" "mijne" Utr Sg P1 ;
   in_Prep = mkPrep "in" ;
-  it_Pron = mkPronoun "het" "het" "zijn" "het" "het" "zijn" "zijne" Neutr Sg P3 ;
+  it_Pron = mkPronoun "het" "het" "zijn" "het" "het" "zijn" "zijne" Neutr Sg P3 **
+             { mergesWithPrep = True ; mergeForm = "er" } ;
 
   less_CAdv = X.mkCAdv "minder" "dan" ;
   many_Det = mkDet "veel" "veel" Pl ;
@@ -90,16 +91,16 @@ concrete StructuralDut of Structural = CatDut, Prelude **
 
   we_Pron = mkPronoun "we" "ons" "ons" "wij" "ons" "onze" "onze" Utr Pl P3 ; ----
 
-  whatSg_IP = {s = \\_ => "wat" ; n = Sg} ;
-  whatPl_IP = {s = \\_ => "wat" ; n = Pl} ;
+  whatSg_IP = {s = \\_ => "wat" ; n = Sg ; mergesWithPrep = True ; mergeForm = "waar"} ;
+  whatPl_IP = {s = \\_ => "wat" ; n = Pl ; mergesWithPrep = True ; mergeForm = "waar"} ;
 
   when_IAdv = ss "wanneer" ;
   when_Subj = ss "als" ;
   where_IAdv = ss "waar" ;
-  which_IQuant = mkPredet "welke" "welk" ;
+  which_IQuant = mkPredet "welke" "welk" ** { mergesWithPrep = True ; mergeForm = "waar"} ;
 
-  whoSg_IP = {s = \\_ => "wie" ; n = Sg} ;
-  whoPl_IP = {s = \\_ => "wie" ; n = Pl} ;
+  whoSg_IP = noMerge ** {s = \\_ => "wie" ; n = Sg} ;
+  whoPl_IP = noMerge ** {s = \\_ => "wie" ; n = Pl} ;
   why_IAdv = ss "waarom" ;
   without_Prep = nomergePrep "zonder" ; -- doesn't combine
   with_Prep = mkPrep "met" ** { mergeForm = "mee" } ;