Add adverb and colon pair to glossary

lib/Language/glossary.pod

@@ -21,6 +21,25 @@ Note that it is still allowed to have a name
     my $s = anon sub triple($x) { 3 * $x }
     say $s.name;        # triple
 
+=head1 Adverb
+
+Generically, an adverb is a named argument to a function.  There are also
+some specific syntax forms that allow adverbs to be tucked into some
+convenient places:
+
+    q:w"foo bar"   # ":w" is a Quotelike form modifier adverb
+    m:g/a|b|c/     # ":g" is also
+    4 +> 5 :rotate # ":rotate" is an operator adverb
+    @h{3}:exists   # ":exists" is also, but is known as a subscript adverb
+
+Adverbs are usually expressed with colon pair notation, and for this
+reason colon pair notation is also known as the adverbial pair form:
+
+    :a(4)          # Same as "a" => 4
+
+Some other forms that use a colon in ways that have adverb-like semantics
+are called adverbial forms.
+
 =head1 Autothreading
 
 Autothreading is what happens if you pass a junction to a sub that expects a
@@ -40,6 +59,28 @@ C<f(1|2|3)> call to be internally executed as C<f(1)|f(2)|f(3)>, and the
 resulting junction is C<2|4|6>. This process of separating junction
 arguments into multiple calls to a function is called I<autothreading>.
 
+=head1 Colon Pair and Colon List
+
+A colon pair is a shorthand syntax used to create or visually present
+a Pair object.  The two most common forms are:
+
+    :a(4)          # Same as "a" => 4,   same as Pair.new(:key<a>,:value(5))
+    :a<4>          # Same as "a" => "4", same as Pair.new(:key<a>,:value<5>)
+
+This is also known as the adverbial pair form.  Note: when the part after
+the colon and before the brackets is not a legal identifier, other
+semantics apply, not all of which produce Pair objects.
+
+Two other common forms are:
+
+    :a             # Same as :a(True)
+    :!a            # Same as :a(False)
+
+A colon list just means that a list that contains only colon pairs,
+does not need commas, or even spaces:
+
+    :a(4):c:!d:c   # Same as a => 4, c => True, d => False, c => True
+
 =head1 Constraint
 
 Constraints are a restriction placed on acceptable types for a parameter