diff --git a/2-ObjectProgramming/6-inheritance.ipynb b/2-ObjectProgramming/6-inheritance.ipynb
index 3e17b3390229e84a5f99e28925d5fc4cdecdf818..ea13477f7af6ba3343857b4cbc04b412373e15fd 100644
--- a/2-ObjectProgramming/6-inheritance.ipynb
+++ b/2-ObjectProgramming/6-inheritance.ipynb
@@ -132,7 +132,7 @@
     "\n",
     "### Multiple layer of inheritance\n",
     "\n",
-    "A child class may also be the parent of another class (unless `final` is used - see later)\n",
+    "A child class may also be the parent of another class (unless `final` keyword is used - we'll see this keyword in [polymorphism notebook](./7-polymorphism.ipynb#final-keyword)).\n",
     "\n"
    ]
   },
@@ -347,9 +347,9 @@
     "    \n",
     "    private:\n",
     "    \n",
-    "        double width_ = -1.e20; // Stupid value that would play havoc if not properly initialized\n",
+    "        double width_ { -1.e20 } ; // Stupid value that would play havoc if not properly initialized\n",
     "                                // - std::optional (C++17) would probably a better choice.\n",
-    "        double length_ = -1.e20;        \n",
+    "        double length_ { -1.e20 }        \n",
     "};"
    ]
   },
diff --git a/2-ObjectProgramming/7-polymorphism.ipynb b/2-ObjectProgramming/7-polymorphism.ipynb
index 0a8362e458fcd7b03783d382727cd85319edd40c..e87af280ed5b12c1c1edd46f14dbc42ff2d9a01a 100644
--- a/2-ObjectProgramming/7-polymorphism.ipynb
+++ b/2-ObjectProgramming/7-polymorphism.ipynb
@@ -942,7 +942,7 @@
    "source": [
     "So you could devise a way to identify which is the dynamic type of your `PolymorphicVehicle` pointer and cast it dynamically to the rightful type so that extended API offered by the derived class is accessible.\n",
     "\n",
-    "If you find this clunky, you are not alone: by experience if you really need to resort to **dynamic_cast** it's probably your data architecture needs some revision. But maybe the mileage vary for other developers, and it's useful to know the possibility exist."
+    "If you find this clunky, you are not alone: by experience if you really need to resort to **dynamic_cast** it's probably your data architecture needs some revision. But maybe the mileage vary for other developers, and it's useful to know the possibility exists."
    ]
   },
   {
@@ -951,7 +951,7 @@
    "source": [
     "## `final` keyword\n",
     "\n",
-    "If you need to specify a class can't be derived, you may stick a `final` keyword in its declaration (from C++11 onward):\n"
+    "If you need to specify a class that can't be derived, you may stick a `final` keyword in its declaration (from C++11 onward):\n"
    ]
   },
   {
@@ -1195,7 +1195,7 @@
    "source": [
     "struct DerivedClass4 : public BaseClass4\n",
     "{\n",
-    "    DerivedClass4() = default;;    \n",
+    "    DerivedClass4() = default;\n",
     "    \n",
     "    virtual std::string ClassName() const;\n",
     "};"
@@ -1287,7 +1287,7 @@
    "source": [
     "struct DerivedClass5 : public BaseClass5\n",
     "{\n",
-    "    DerivedClass5() = default;;    \n",
+    "    DerivedClass5() = default; \n",
     "    \n",
     "    virtual std::string ClassName() const;\n",
     "};"