Return word commentary

main.rb

@@ -25,9 +25,12 @@ get '/words/:id' do
   Context.call db_pool: $DB_POOL, user_lang_id: 2 do |context|
     word_id = Integer params[:id]
 
+    word_info = context.word_info(word_id)
+
     json({
-      primary_form: context.primary_form(word_id),
+      primary_form: word_info[:primary_form],
       part_of_speech: context.part_of_speech_name(word_id),
+      commentary: word_info[:commentary],
       translations: context.translations(word_id),
       examples: context.examples(word_id),
     })
@@ -70,18 +73,26 @@ private
 public
 
   ##
-  # @return [String, nil]
+  # @return [Hash{Symbol => String}, nil]
   #
-  def primary_form(word_id)
+  def word_info(word_id)
     word_id = Integer word_id
 
-    column = @db_conn.exec_params(
-      'SELECT primary_form FROM words WHERE id = $1',
+    row = @db_conn.exec_params(
+      'SELECT primary_form, commentary FROM words WHERE id = $1',
       [word_id],
-    ).values.first&.first
+    ).to_a.first
 
-    str = String(column).strip.freeze
-    str unless str.empty?
+    primary_form = String(row['primary_form']).strip.freeze
+    primary_form = nil if primary_form.empty?
+
+    commentary = String(row['commentary']).strip.freeze
+    commentary = nil if commentary.empty?
+
+    {
+      primary_form: primary_form,
+      commentary: commentary,
+    }.freeze
   end
 
   ##