The shape of language tags

I have several shapes that specify sh:datatype xsd:string but I find
strings with language tags are being flagged as violations, for example, in
the shacl playground I modify the example turtle to read

ex:Bob
    a schema:Person ;
    schema:givenName "Robert"@en ;
    schema:familyName "Junior" ;
    schema:birthDate "1971-07-07"^^xsd:date ;
    schema:deathDate "1968-09-10"^^xsd:date ;
    schema:address ex:BobsAddress .

and I get

[
a sh:ValidationResult ;
sh:resultSeverity sh:Violation ;
sh:sourceConstraintComponent sh:DatatypeConstraintComponent ;
sh:sourceShape _:n1 ;
sh:focusNode <http://example.org/ns#Bob> ;
sh:value "Robert"@en ;
sh:resultPath schema:givenName ;
sh:resultMessage "Value does not have datatype xsd:string" ;
] .

This happens with both the playground's js-based and with the apache java
implementations.  How do I get around this?


-- 
Gary Lawrence Murphy <gary@schemaapp.com> - Hunch Manifest, 15 Wyndham N
'C', Guelph