diff --git a/docs/source/usage.rst b/docs/source/usage.rst
index 24da98a..ac4d61b 100644
--- a/docs/source/usage.rst
+++ b/docs/source/usage.rst
@@ -5,7 +5,7 @@ Usage
 Open an existing ontology
 -------------------------
 
-To open an ontology use the :func:`~pyhornedowl.open_ontology` function. It guesses the serialization of the ontology by the file extension or tries all parsers. Alternatively, specify the serialization format explicitely with the ``serialization`` option.
+To open an ontology use the :func:`~pyhornedowl.open_ontology` function. It guesses the serialization of the ontology by the file extension or tries all parsers. Alternatively, specify the serialization format explicitly with the ``serialization`` option.
 
 .. code-block:: python
    
@@ -20,7 +20,7 @@ To open an ontology use the :func:`~pyhornedowl.open_ontology` function. It gues
 Save an ontology
 ----------------
 
-Use the :func:`PyIndexedOntology.save_to_file <pyhornedowl.PyIndexedOntology.save_to_file>` function to write the ontology to a file. Again, the serialization is guessed by the file extension and defaults to OWL/XML. Alternatively, specify the serialization format explicitely with the ``serialization`` option.
+Use the :func:`PyIndexedOntology.save_to_file <pyhornedowl.PyIndexedOntology.save_to_file>` function to write the ontology to a file. Again, the serialization is guessed by the file extension and defaults to OWL/XML. Alternatively, specify the serialization format explicitly with the ``serialization`` option.
 
 .. code-block:: python
 
@@ -48,7 +48,7 @@ The preferred way to create IRIs is through an ontology instance as it enables H
 
     assert i1 == i2
 
-The :func:`PyIndexedOntology.iri <pyhornedowl.PyIndexedOntology.iri>` function guesses if you passed it an absolute IRI or a CURIE based on the existence of ``://`` in the value. This is also true for all other convenience functions accepting IRIs as an argument. You can explicitely specify if the value is an absolute IRI or a CURIE by using the optional parameter ``absolute``.
+The :func:`PyIndexedOntology.iri <pyhornedowl.PyIndexedOntology.iri>` function guesses if you passed it an absolute IRI or a CURIE based on the existence of ``://`` in the value. This is also true for all other convenience functions accepting IRIs as an argument. You can explicitly specify if the value is an absolute IRI or a CURIE by using the optional parameter ``absolute``.
 
 An exception to this is the the function :func:`PyIndexedOntology.curie <pyhornedowl.PyIndexedOntology.curie>` which only accepts CURIEs.