diff --git a/packages/flutter/lib/src/rendering/box.dart b/packages/flutter/lib/src/rendering/box.dart
index f01a45e621e..3ac00d990fe 100644
--- a/packages/flutter/lib/src/rendering/box.dart
+++ b/packages/flutter/lib/src/rendering/box.dart
@@ -1989,7 +1989,7 @@ abstract class RenderBox extends RenderObject {
             'RenderBox.size accessed beyond the scope of resize, layout, or '
             'permitted parent access. RenderBox can always access its own size, '
             'otherwise, the only object that is allowed to read RenderBox.size '
-            'is its parent, if they have said they will. It you hit this assert '
+            'is its parent, if they have said they will. If you hit this assert '
             'trying to access a child\'s size, pass "parentUsesSize: true" to '
             "that child's layout().",
           );