diff --git a/custom.el b/custom.el
index cd57a00..6145b0c 100644
--- a/custom.el
+++ b/custom.el
@@ -9,7 +9,7 @@
  '(elpy-eldoc-show-current-function nil)
  '(package-selected-packages
    (quote
-    (powershell diffview ivy-hydra window-numbering php-mode swiper mode-line-bell htmlize cython-mode blacken dired-narrow lua-mode browse-kill-ring clipmon free-keys org-link-minor-mode js2-mode js2-refactor xref-js2 python-django visual-regexp-steroids pcre2el vimrc-mode iedit transient magit dracula-theme flycheck elpy ein better-defaults ssh-config-mode yaml-mode apache-mode web-mode undo-tree)))
+    (string-inflection tiny powershell diffview ivy-hydra window-numbering php-mode swiper mode-line-bell htmlize cython-mode blacken dired-narrow lua-mode browse-kill-ring clipmon free-keys org-link-minor-mode js2-mode js2-refactor xref-js2 python-django visual-regexp-steroids pcre2el vimrc-mode iedit transient magit dracula-theme flycheck elpy ein better-defaults ssh-config-mode yaml-mode apache-mode web-mode undo-tree)))
  '(reb-re-syntax (quote string)))
 (custom-set-faces
  ;; custom-set-faces was added by Custom.
diff --git a/settings.org b/settings.org
index e271386..b193d0d 100644
--- a/settings.org
+++ b/settings.org
@@ -1,5 +1,29 @@
 * Global
 ** Add features/modes
+*** string-inflection
+#+BEGIN_SRC emacs-lisp
+(require 'string-inflection)
+
+;; C-q C-u is the key bindings similar to Vz Editor.
+(global-set-key (kbd "C-M-,") 'my-string-inflection-cycle-auto)
+
+(defun my-string-inflection-cycle-auto ()
+  "switching by major-mode"
+  (interactive)
+  (cond
+   ;; for emacs-lisp-mode
+   ((eq major-mode 'emacs-lisp-mode)
+    (string-inflection-all-cycle))
+   ;; for python
+   ((eq major-mode 'python-mode)
+    (string-inflection-python-style-cycle))
+   ;; for java
+   ((eq major-mode 'java-mode)
+    (string-inflection-java-style-cycle))
+   (t
+    ;; default
+    (string-inflection-ruby-style-cycle))))
+#+END_SRC
 *** undo-tree
 #+begin_src emacs-lisp
 (require 'undo-tree)