diff --git a/css-properties-values-api/Overview.bs b/css-properties-values-api/Overview.bs
index 115cd7e1..15437d7c 100644
--- a/css-properties-values-api/Overview.bs
+++ b/css-properties-values-api/Overview.bs
@@ -87,7 +87,7 @@ allow custom properties to directly impact paint and layout behaviours respectiv
Registered Custom Properties {#behavior-of-custom-properties}
=============================================================
-A [=custom property=] can become a registered custom property,
+A [=custom property=] can become a registered custom property,
making it act more like a UA-defined property:
giving it a syntax that's checked by the UA,
an initial value,
@@ -209,7 +209,8 @@ or the [=guaranteed-invalid value=]).
Otherwise, attempt to [=CSS/parse=] the property's value
according to its registered syntax.
If this fails,
-the [=computed value=] is the [=guaranteed-invalid value=].
+the declaration is [=invalid at computed-value time=]
+and the [=computed value=] is determined accordingly.
If it succeeds,
the [=computed value=] depends on the specifics of the syntax:
@@ -569,7 +570,7 @@ If omitted, the [=initial value=] of the property is the [=guaranteed-invalid va
Otherwise,
if the value of the 'syntax' descriptor is not the [=universal syntax definition=],
-the following conditions must be met for the the ''@property'' rule to be valid:
+the following conditions must be met for the ''@property'' rule to be valid:
* The 'initial-value' descriptor must be present.
* The 'initial-value' descriptor's value must [=consume a syntax definition|parse successfully=]
@@ -974,7 +975,7 @@ Parsing The Syntax String {#parsing-syntax}
: syntax definition
:: An object consisting of a list of syntax components.
-: universal syntax definition
+: universal syntax definition
:: A special syntax definition which accepts any valid token stream.
### Consume a Syntax Definition ### {#consume-syntax-definition}