I grew up with sign language, not spoken language.
Deaf people signed, yeah, but only with each other.
If a hearing person joined in, they'd elbow each other to point out the presence of the hearing person and they'd quickly switch to speech.
And once the hearing person left, they'd switch back.
But that wasn't really proper sign language. Rather, it was signing with Dutch clearly present in the mouthing.
That was quite widespread in the Netherlands.
During my research into education and sign language, I was told by everyone that they used proper sign language in Groningen.
So then I went to look into that and it turned out not to be the case at all.
They were all using a signing system.
Groningen had copied that from France.
The catholic school had also copied that from France.
They copied it from l'Epée, you know.
A signing system with Dutch sentences and grammar.
Nowadays we'd call it NmG (Sign-supported Dutch).
So that's it, in 1800 they taught NmG!
They used those rigid signs with [mondbeeld], one by one.
You can see it in an old film about the catholic school.
The museum on deaf education in Gestel, that museum.
They have a film with alumni from Gestel using signs from Gestel.
They have signs for the articles, et cetera. They had signs for that.
Also for words like 'is'. It's simply NmG. A signing system.
Throughout Dutch history there has never, ever been a sign language in our schools. There has been a signing system.
Deaf people do use sign language among each other.
The grammar of which is completely different.
But in schools, no, they used a signing system using the grammar of spoken Dutch.