diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index cc4a089..7d222d4 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -862,7 +862,7 @@
 /// SemaBuiltinObjectSize - Handle __builtin_object_size(void *ptr,
 /// int type). This simply type checks that type is one of the defined
 /// constants (0-3).
-// For compatability check 0-3, llvm only handles 0 and 2.
+// For compatibility check 0-3, llvm only handles 0 and 2.
 bool Sema::SemaBuiltinObjectSize(CallExpr *TheCall) {
   llvm::APSInt Result;
   
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 101ade7..0cb9361 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -1474,7 +1474,7 @@
       assert(PrevI != SuperMethodDecl->param_end() && "Param mismatch");
       QualType T1 = Context.getCanonicalType((*ParamI)->getType());
       QualType T2 = Context.getCanonicalType((*PrevI)->getType());
-      // If type of arguement of method in this class does not match its
+      // If type of argument of method in this class does not match its
       // respective argument type in the super class method, issue warning;
       if (!Context.typesAreCompatible(T1, T2)) {
         Diag((*ParamI)->getLocation(), diag::ext_typecheck_base_super)
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 73825ba..2cdd824 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -348,7 +348,7 @@
 
 /// UsualUnaryConversions - Performs various conversions that are common to most
 /// operators (C99 6.3). The conversions of array and function types are
-/// sometimes surpressed. For example, the array->pointer conversion doesn't
+/// sometimes suppressed. For example, the array->pointer conversion doesn't
 /// apply if the array is an argument to the sizeof or address (&) operators.
 /// In these instances, this routine should *not* be called.
 ExprResult Sema::UsualUnaryConversions(Expr *E) {
diff --git a/lib/Sema/SemaObjCProperty.cpp b/lib/Sema/SemaObjCProperty.cpp
index 95a365c..6c4469c 100644
--- a/lib/Sema/SemaObjCProperty.cpp
+++ b/lib/Sema/SemaObjCProperty.cpp
@@ -685,7 +685,7 @@
 
 /// ComparePropertiesInBaseAndSuper - This routine compares property
 /// declarations in base and its super class, if any, and issues
-/// diagnostics in a variety of inconsistant situations.
+/// diagnostics in a variety of inconsistent situations.
 ///
 void Sema::ComparePropertiesInBaseAndSuper(ObjCInterfaceDecl *IDecl) {
   ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();