diff --git a/effects/blur/blur.cpp b/effects/blur/blur.cpp
index 83012b160d..c8b39b6cbb 100644
--- a/effects/blur/blur.cpp
+++ b/effects/blur/blur.cpp
@@ -245,7 +245,7 @@ void BlurEffect::prePaintWindow(EffectWindow* w, WindowPrePaintData& data, int t
     }
     data.clip = newClip;
 
-    // we dont have to blur a region we dont see
+    // we don't have to blur a region we don't see
     m_currentBlur -= newClip;
     // if we have to paint a non-opaque part of this window that intersects with the
     // currently blurred region we have to redraw the whole region
@@ -268,7 +268,7 @@ void BlurEffect::prePaintWindow(EffectWindow* w, WindowPrePaintData& data, int t
     }
     m_currentBlur |= expandedBlur;
 
-    // we dont consider damaged areas which are occluded and are not
+    // we don't consider damaged areas which are occluded and are not
     // explicitly damaged by this window
     m_damagedArea -= data.clip;
     m_damagedArea |= data.paint;
diff --git a/geometry.cpp b/geometry.cpp
index 5c0f303e53..071682ab53 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -2631,7 +2631,7 @@ void Client::finishMoveResize(bool cancel)
         setQuickTileMode(electricMode);
         const ElectricBorder border = electricBorderFromMode(electricMode);
         if (border == ElectricNone)
-            kDebug(1212) << "invalid electric mode" << electricMode << "leading to invalid array acces,\
+            kDebug(1212) << "invalid electric mode" << electricMode << "leading to invalid array access,\
                                                                         this should not have happened!";
 #ifdef KWIN_BUILD_SCREENEDGES
         else
diff --git a/scene.cpp b/scene.cpp
index eb3e4172ec..8509400dd2 100644
--- a/scene.cpp
+++ b/scene.cpp
@@ -324,7 +324,7 @@ void Scene::paintSimpleScreen(int orig_mask, QRegion region)
 
             // Clip out the client area, so we only draw the rest in the next pass
             data->region -= data->clip;
-            // if prePaintWindow didnt change the clipping area we only have to paint
+            // if prePaintWindow didn't change the clipping area we only have to paint
             // the decoration
             if (data-> clip == data.key()->clientShape().translated(data.key()->x(), data.key()->y())) {
                 data->mask |= PAINT_DECORATION_ONLY;
diff --git a/scene_opengl.cpp b/scene_opengl.cpp
index 22f323f7dd..2346a1ea77 100644
--- a/scene_opengl.cpp
+++ b/scene_opengl.cpp
@@ -656,7 +656,7 @@ void SceneOpenGL::Window::paintDecoration(const QPixmap* decoration, TextureType
     // This is especially needed if we draw the opaque part of the window
     // and the decoration in two different passes (as we in Scene::paintSimpleWindow do).
     // Otherwise we run into the situation that in the first pass there are some
-    // pending decoration repaints but we dont paint the decoration and in the
+    // pending decoration repaints but we don't paint the decoration and in the
     // second pass it's the other way around.
     if (quads.isEmpty())
         return;
diff --git a/scene_opengl_glx.cpp b/scene_opengl_glx.cpp
index 5eeb5c7406..9ceeb761db 100644
--- a/scene_opengl_glx.cpp
+++ b/scene_opengl_glx.cpp
@@ -672,7 +672,7 @@ void SceneOpenGL::Texture::bind()
 {
     glEnable(mTarget);
     glBindTexture(mTarget, mTexture);
-    // if one of the GLTexture::load functions is called, the glxpixmap doesnt
+    // if one of the GLTexture::load functions is called, the glxpixmap doesn't
     // have to exist
     if (options->glStrictBinding && glxpixmap) {
         glXReleaseTexImageEXT(display(), glxpixmap, GLX_FRONT_LEFT_EXT);
@@ -691,7 +691,7 @@ void SceneOpenGL::Texture::unbind()
     if (hasGLVersion(1, 4, 0)) {
         glTexEnvf(GL_TEXTURE_FILTER_CONTROL, GL_TEXTURE_LOD_BIAS, 0.0f);
     }
-    // if one of the GLTexture::load functions is called, the glxpixmap doesnt
+    // if one of the GLTexture::load functions is called, the glxpixmap doesn't
     // have to exist
     if (options->glStrictBinding && glxpixmap) {
         glBindTexture(mTarget, mTexture);