The effects of Bill 101 appear to be having their intended impact.
Four out of five students are attending French schools in Montreal and that's up from nearly 64% from 1971.
Among allophones, those whose mother tongue is neither French nor English, the number increased from almost 15% in 1971 to nearly 90% in 2015.
The studies done by the OQLF - Office Québécoise de la langue française - also report a 20% increase in the number of anglophones attending French schools since 1976, for a total of 30% in 2015.
Gabby Szabo and her husband both went to French immersion where they got a basic French language education so that's why their young daughter is now in French school.
"It does limit us professionally and for both of us, we wanted her to speak French better than her parents," said Szabo.
"Our family is here and I want her to have those choices."
Jack Jedwab, president of the Association for Canadian Studies, said it's a challenge for parents.
"Clearly what you do need although in order to make sure you've got the right language skills is to be able to have an opportunity to interact in that language practically, not just learning from the books," said Jedwab.
Jedwab said while it's positive for the protection of the French language, it is less so for English schools struggling with declining enrolment.
"There's a concern that on the one hand, the legislation has served to encourage those who are eligible for English-language school to go to French-language school and on the other hand, it's not permitting them to reach out to potentially important clientele, the most important clientele, as regards growth in enrolment in schools," said Jedwab.
The studies covered preschool up to CEGEP.