diff --git a/src/Forms/TreeDropdownField.php b/src/Forms/TreeDropdownField.php
index b27dae2e5..a6f21ec14 100644
--- a/src/Forms/TreeDropdownField.php
+++ b/src/Forms/TreeDropdownField.php
@@ -501,7 +501,7 @@ class TreeDropdownField extends FormField
         // Begin marking
         $markingSet->markPartialTree();
 
-        // Explicitely mark our search results if necessary
+        // Explicitly mark our search results if necessary
         foreach ($this->searchIds as $id => $marked) {
             if ($marked) {
                 $object = $this->objectForKey($id);
diff --git a/src/ORM/Hierarchy/Hierarchy.php b/src/ORM/Hierarchy/Hierarchy.php
index b482bc025..6f6d2e84c 100644
--- a/src/ORM/Hierarchy/Hierarchy.php
+++ b/src/ORM/Hierarchy/Hierarchy.php
@@ -30,7 +30,7 @@ class Hierarchy extends DataExtension
 {
     /**
      * The lower bounds for the amount of nodes to mark. If set, the logic will expand nodes until it reaches at least
-     * this number, and then stops. Root nodes will always show regardless of this settting. Further nodes can be
+     * this number, and then stops. Root nodes will always show regardless of this setting. Further nodes can be
      * lazy-loaded via ajax. This isn't a hard limit. Example: On a value of 10, with 20 root nodes, each having 30
      * children, the actual node count will be 50 (all root nodes plus first expanded child).
      *
@@ -286,7 +286,7 @@ class Hierarchy extends DataExtension
 
     /**
      * Return the number of direct children. By default, values are cached after the first invocation. Can be
-     * augumented by {@link augmentNumChildrenCountQuery()}.
+     * augmented by {@link augmentNumChildrenCountQuery()}.
      *
      * @param bool $cache Whether to retrieve values from cache
      * @return int
@@ -322,7 +322,7 @@ class Hierarchy extends DataExtension
     /**
      * Pre-populate any appropriate caches prior to rendering a tree.
      * This is used to allow for the efficient rendering of tree views, notably in the CMS.
-     * In the cace of Hierarchy, it caches numChildren values. Other extensions can provide an
+     * In the case of Hierarchy, it caches numChildren values. Other extensions can provide an
      * onPrepopulateTreeDataCache(DataList $recordList = null, array $options) methods to hook
      * into this event as well.
      *
diff --git a/tests/php/Forms/TreeDropdownFieldTest.php b/tests/php/Forms/TreeDropdownFieldTest.php
index 17de5c8d3..3d78c7ab3 100644
--- a/tests/php/Forms/TreeDropdownFieldTest.php
+++ b/tests/php/Forms/TreeDropdownFieldTest.php
@@ -56,7 +56,7 @@ class TreeDropdownFieldTest extends SapphireTest
     {
         $field = new TreeDropdownField('TestTree', 'Test tree', Folder::class);
 
-        // case insensitive search against keyword 'sub' for folders
+        // case-insensitive search against keyword 'sub' for folders
         $request = new HTTPRequest('GET', 'url', ['search'=>'sub', 'format' => 'json']);
         $request->setSession(new Session([]));
         $response = $field->tree($request);
@@ -87,7 +87,7 @@ class TreeDropdownFieldTest extends SapphireTest
     {
         $field = new TreeDropdownField('TestTree', 'Test tree', Folder::class);
 
-        // case insensitive search against keyword 'sub' for folders
+        // case-insensitive search against keyword 'sub' for folders
         $request = new HTTPRequest('GET', 'url', ['search'=>'sub', 'format' => 'json', 'flatList' => '1']);
         $request->setSession(new Session([]));
         $response = $field->tree($request);
@@ -176,7 +176,7 @@ class TreeDropdownFieldTest extends SapphireTest
     {
         $field = new TreeDropdownField('TestTree', 'Test tree', Folder::class);
 
-        // case insensitive search against keyword 'sub' for folders
+        // case-insensitive search against keyword 'sub' for folders
         $request = new HTTPRequest('GET', 'url', ['search'=>'sub']);
         $request->setSession(new Session([]));
         $response = $field->tree($request);
@@ -214,7 +214,7 @@ class TreeDropdownFieldTest extends SapphireTest
 
         $field = new TreeDropdownField('TestTree', 'Test tree', File::class);
 
-        // case insensitive search against keyword 'sub' for files
+        // case-insensitive search against keyword 'sub' for files
         $request = new HTTPRequest('GET', 'url', ['search'=>'sub']);
         $request->setSession(new Session([]));
         $response = $field->tree($request);
@@ -340,7 +340,7 @@ class TreeDropdownFieldTest extends SapphireTest
         $treeBaseID = $this->idFromFixture(Folder::class, 'folder1');
         $field = new TreeDropdownField('TestTree', 'Test tree', Folder::class);
 
-        // getSchemaDataDefaults needs the field to be attach to a form
+        // getSchemaDataDefaults needs the field to be attached to a form
         new Form(
             null,
             'mock',
diff --git a/tests/php/ORM/HierarchyCachingTest.php b/tests/php/ORM/HierarchyCachingTest.php
index 7f101fb50..2d3de8dfb 100644
--- a/tests/php/ORM/HierarchyCachingTest.php
+++ b/tests/php/ORM/HierarchyCachingTest.php
@@ -48,10 +48,10 @@ class HierachyCacheTest extends SapphireTest
             [TestObject::class, 'obj2', true, 2, 'Root object numChildren should count direct children when cache'],
             [TestObject::class, 'obj3a', false, 2, 'Sub object numChildren should count direct children'],
             [TestObject::class, 'obj3a', true, 2, 'Sub object numChildren should count direct children when cache'],
-            [TestObject::class, 'obj3d', false, 0, 'Childess Sub object numChildren should be 0'],
-            [TestObject::class, 'obj3d', true, 0, 'Childess Sub object numChildren should be 0 when cache'],
+            [TestObject::class, 'obj3d', false, 0, 'Childless Sub object numChildren should be 0'],
+            [TestObject::class, 'obj3d', true, 0, 'Childless Sub object numChildren should be 0 when cache'],
             [HideTestObject::class, 'obj4', false, 1, 'Hidden object should not be included in count'],
-            [HideTestObject::class, 'obj4', true, 1, 'Hidden object should not be included in couunt when cache']
+            [HideTestObject::class, 'obj4', true, 1, 'Hidden object should not be included in count when cache']
         ];
     }
 
@@ -68,7 +68,7 @@ class HierachyCacheTest extends SapphireTest
         $this->assertEquals($expected, $actual, $message);
 
         if ($cache) {
-            // When caching is eanbled, try re-accessing the numChildren value to make sure it doesn't change.
+            // When caching is enabled, try re-accessing the numChildren value to make sure it doesn't change.
             $actual = $node->numChildren($cache);
             $this->assertEquals($expected, $actual, $message);
         }
diff --git a/tests/php/ORM/HierarchyTest.php b/tests/php/ORM/HierarchyTest.php
index f22a313ad..6d4676377 100644
--- a/tests/php/ORM/HierarchyTest.php
+++ b/tests/php/ORM/HierarchyTest.php
@@ -258,7 +258,7 @@ class HierarchyTest extends SapphireTest
         $this->assertEquals('Obj 2 » Obj 2a » Obj 2aa', $obj2aa->getBreadcrumbs());
     }
 
-    public function testNoHideFromHeirarchy()
+    public function testNoHideFromHierarchy()
     {
         /** @var HierarchyTest\HideTestObject $obj4 */
         $obj4 = $this->objFromFixture(HierarchyTest\HideTestObject::class, 'obj4');
@@ -271,7 +271,7 @@ class HierarchyTest extends SapphireTest
         $this->assertEquals($obj4->liveChildren()->Count(), 2);
     }
 
-    public function testHideFromHeirarchy()
+    public function testHideFromHierarchy()
     {
         HierarchyTest\HideTestObject::config()->update(
             'hide_from_hierarchy',