Use Formatter::pluralize where possible.

Library/Homebrew/cask/lib/hbc/cli/doctor.rb

@@ -55,8 +55,7 @@ module Hbc
       end
 
       def self.cask_count_for_tap(tap)
-        count = tap.cask_files.count
+        Formatter.pluralize(tap.cask_files.count, "cask")
-        "#{count} #{count == 1 ? "cask" : "casks"}"
       rescue StandardError
         "0 #{error_string "error reading #{tap.path}"}"
       end

Library/Homebrew/cmd/uninstall.rb

@@ -55,7 +55,7 @@ module Homebrew
 
             if rack.directory?
               versions = rack.subdirs.map(&:basename)
-              verb = versions.length == 1 ? "is" : "are"
+              verb = Formatter.pluralize(versions.length, "is", "are")
               puts "#{keg.name} #{versions.join(", ")} #{verb} still installed."
               puts "Remove all versions with `brew uninstall --force #{keg.name}`."
             end
@@ -109,11 +109,11 @@ module Homebrew
     protected
 
     def are(items)
-      items.count == 1 ? "is" : "are"
+      Formatter.pluralize(items.count, "is", "are", show_count: false)
     end
 
     def they(items)
-      items.count == 1 ? "it" : "they"
+      Formatter.pluralize(items.count, "it", "they", show_count: false)
     end
 
     def list(items)

Library/Homebrew/utils/formatter.rb

@@ -91,17 +91,17 @@ module Formatter
     output
   end
 
-  def pluralize(count, singular, plural = nil)
+  def pluralize(count, singular, plural = nil, show_count: true)
-    return "#{count} #{singular}" if count == 1
+    return (show_count ? "#{count} #{singular}" : singular.to_s) if count == 1
 
-    *adjectives, noun = singular.split(" ")
+    *adjectives, noun = singular.to_s.split(" ")
 
     plural ||= {
       "formula" => "formulae",
     }.fetch(noun, "#{noun}s")
 
-    words = adjectives << plural
+    words = adjectives.push(plural).join(" ")
 
-    "#{count} #{words.join(" ")}"
+    show_count ? "#{count} #{words}" : words
   end
 end