Fixing minor grammar in the parcels structure tutorial

Author: michaeldenes

docs/examples/tutorial_parcels_structure.ipynb

@@ -13,9 +13,9 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The flexibility of Parcels allows for a wide range of applications and to build complex simulations. In order to help structuring your code, this tutorial describes the structure that a Parcels script uses.\n",
+    "The flexibility of Parcels allows for a wide range of applications and to build complex simulations. In order to help structure your code, this tutorial describes the structure that a Parcels script uses.\n",
     "\n",
-    "Code that uses Parcels is generally build up from four different components:\n"
+    "Code that uses Parcels is generally built up from four different components:\n"
    ]
   },
   {