Update spec/index.html

Co-authored-by: Olaf Hartig <[email protected]>

spec/index.html

@@ -190,7 +190,7 @@ <h3>Triple Terms</h3>
       called a <dfn>reified triple</dfn>.
       The <a>subject</a> of that <a>triple</a> is called a <dfn>reifier</dfn>.
       Assertions on the <a>triple term</a> are made using the <a>reifier</a>.
-      Some concrete syntaxes may provide a syntax for specifyig <a>reified triples</a>.</p>
+      Concrete syntaxes may provide a special notation for specifying <a>reified triples</a>.</p>
 
     <p class="note">Using the <a>reifier</a> as an indirect way of referencing a <a>triple term</a>
       allows multiple groups of assertions to be separated from each other,