diff --git a/client/src/controllers/CountController.ts b/client/src/controllers/CountController.ts
index b643b81fd1..0a9c404569 100644
--- a/client/src/controllers/CountController.ts
+++ b/client/src/controllers/CountController.ts
@@ -29,7 +29,7 @@ export class CountController extends Controller<HTMLFormElement> {
   declare containerValue: string;
   /** selector string, used to find the elements to count within the container */
   declare findValue: string;
-  /** override pluralisation strings, e.g. `data-w-count-labels-value='["One item","Many items"]'` */
+  /** override pluralization strings, e.g. `data-w-count-labels-value='["One item","Many items"]'` */
   declare labelsValue: string[];
   /** minimum value, anything equal or below will trigger blank labels in the UI */
   declare minValue: number;
diff --git a/client/src/controllers/DismissibleController.ts b/client/src/controllers/DismissibleController.ts
index ddbb7b5406..dad6e78005 100644
--- a/client/src/controllers/DismissibleController.ts
+++ b/client/src/controllers/DismissibleController.ts
@@ -3,7 +3,7 @@ import { WAGTAIL_CONFIG } from '../config/wagtailConfig';
 
 /**
  * Updates the server, using a PATCH request when the toggle is clicked on a dismissible
- * element initialised by DismissibleController
+ * element initialized by DismissibleController
  *
  * @param data - The dismissible represented as an object with keys as
  * the id and its new state: whether it is dismissed (boolean)
@@ -29,8 +29,8 @@ export const updateDismissibles = (
 
 /**
  * Adds the ability to make an element dismissible so that it updates it's class and makes an async request.
- * Initialise such elements with a default handler that performs the dismissal.
- * This only initialises elements that are rendered by the server (if they have the data attr), so elements
+ * Initialize such elements with a default handler that performs the dismissal.
+ * This only initializes elements that are rendered by the server (if they have the data attr), so elements
  * that are rendered by the client (e.g. React) needs to be handled separately.
  *
  * @example
diff --git a/client/src/controllers/PreviewController.ts b/client/src/controllers/PreviewController.ts
index 4e14db2af7..5c44ad4559 100644
--- a/client/src/controllers/PreviewController.ts
+++ b/client/src/controllers/PreviewController.ts
@@ -557,7 +557,7 @@ export class PreviewController extends Controller<HTMLElement> {
    * @returns whether the data is valid
    */
   async checkAndUpdatePreview() {
-    // Small performance optimisation: the hasChanges() method will not be called
+    // Small performance optimization: the hasChanges() method will not be called
     // if there is a pending update due to the || operator short-circuiting
     if (this.updatePromise || !this.hasChanges()) return undefined;
     return this.setPreviewData();
diff --git a/client/src/controllers/SlugController.ts b/client/src/controllers/SlugController.ts
index 3d1eccac18..03060d12f4 100644
--- a/client/src/controllers/SlugController.ts
+++ b/client/src/controllers/SlugController.ts
@@ -79,7 +79,7 @@ export class SlugController extends Controller<HTMLInputElement> {
    * or can be used to simply return the transformed value.
    *
    * The urlify (Django port) function performs extra processing on the string &
-   * is more suitable for creating a slug from the title, rather than sanitising manually.
+   * is more suitable for creating a slug from the title, rather than sanitizing manually.
    * If the urlify util returns an empty string it will fall back to the slugify method.
    *
    * If a custom event with detail.value is provided, that value will be used
diff --git a/client/src/controllers/SwapController.ts b/client/src/controllers/SwapController.ts
index 0085295093..2d1fe7e8a9 100644
--- a/client/src/controllers/SwapController.ts
+++ b/client/src/controllers/SwapController.ts
@@ -91,7 +91,7 @@ export class SwapController extends Controller<
   replaceLazy?: { (...args: any[]): void; cancel(): void };
   /** Debounced function to search results and then replace the DOM */
   searchLazy?: { (...args: any[]): void; cancel(): void };
-  /** Debounced function to submit the serialised form and then replace the DOM */
+  /** Debounced function to submit the serialized form and then replace the DOM */
   submitLazy?: { (...args: any[]): void; cancel(): void };
   /** A function that writes the HTML to the target */
   writeDeferred?: () => Promise<string>;
@@ -227,7 +227,7 @@ export class SwapController extends Controller<
 
   /**
    * Update the target element's content with the response from a request based on the input's form
-   * values serialised. Do not account for anything in the main location/URL, simply replace the content within
+   * values serialized. Do not account for anything in the main location/URL, simply replace the content within
    * the target element.
    */
   submit() {
@@ -235,7 +235,7 @@ export class SwapController extends Controller<
     let data: FormData | undefined = new FormData(form);
 
     let url = this.srcValue;
-    // serialise the form to a query string if it's a GET request
+    // serialize the form to a query string if it's a GET request
     if (form.getAttribute('method')?.toUpperCase() === 'GET') {
       // cast as any to avoid https://github.com/microsoft/TypeScript/issues/43797
       url += '?' + new URLSearchParams(data as any).toString();