diff --git a/jquery/jquery-tests.ts b/jquery/jquery-tests.ts
index 6981118e1..0516fa82c 100644
--- a/jquery/jquery-tests.ts
+++ b/jquery/jquery-tests.ts
@@ -2218,7 +2218,7 @@ function test_isEmptyObject() {
     jQuery.isEmptyObject({ foo: "bar" });
 }
 
-function test_isFuction() {
+function test_isFunction() {
     function stub() { };
     var objs: any[] = [
           function () { },
diff --git a/jquery/jquery.d.ts b/jquery/jquery.d.ts
index 69e80ce21..b941077c9 100644
--- a/jquery/jquery.d.ts
+++ b/jquery/jquery.d.ts
@@ -936,12 +936,47 @@ interface JQueryStatic {
      */
     inArray<T>(value: T, array: T[], fromIndex?: number): number;
 
+    /**
+     * Determine whether the argument is an array.
+     *
+     * @param obj Object to test whether or not it is an array.
+     */
     isArray(obj: any): boolean;
+    /**
+     * Check to see if an object is empty (contains no enumerable properties).
+     *
+     * @param obj The object that will be checked to see if it's empty.
+     */
     isEmptyObject(obj: any): boolean;
+    /**
+     * Determine if the argument passed is a Javascript function object.
+     *
+     * @param obj Object to test whether or not it is a function.
+     */
     isFunction(obj: any): boolean;
+    /**
+     * Determines whether its argument is a number.
+     *
+     * @param obj The value to be tested.
+     */
     isNumeric(value: any): boolean;
+    /**
+     * Check to see if an object is a plain object (created using "{}" or "new Object").
+     *
+     * @param obj The object that will be checked to see if it's a plain object.
+     */
     isPlainObject(obj: any): boolean;
+    /**
+     * Determine whether the argument is a window.
+     *
+     * @param obj Object to test whether or not it is a window.
+     */
     isWindow(obj: any): boolean;
+    /**
+     * Check to see if a DOM node is within an XML document (or is an XML document).
+     *
+     * @param node he DOM node that will be checked to see if it's in an XML document.
+     */
     isXMLDoc(node: Node): boolean;
 
     makeArray(obj: any): any[];