Fixed grammar

README.md

@@ -24,7 +24,7 @@ for finding:
 * the shortest path between vertices,
 * the path with the lowest/highest weight (for weighted directed graphs),
 * all paths connecting two vertices,
-* the shortest paths from a vertice to all connected vertices,
+* the shortest paths from a vertex to all connected vertices,
 * cycles,
 * a topological ordering of the graph vertices.
 
@@ -65,7 +65,7 @@ To use this library include [`directed_graph`][directed_graph] as a dependency i
 example below shows how to construct an object of type [`DirectedGraph`][DirectedGraph].
 
 The graph classes provided by this library are generic with type argument
-`T extends Object`, that is vertice must be non-nullable.
+`T extends Object`, that is `T` must be non-nullable.
 Graph vertices can be sorted if `T is Comparable` or
 if a custom comparator function is provided. In the example below, a custom
 comparator is used to sort vertices in inverse lexicographical order.