Caroline Jones raised the issue of the Welsh language commissioner's call for "radical change" in education to reach a target of 1m Welsh-speakers by 2050.
The UKIP AM said she disagreed with Meri Huws's call for compulsory Welsh medium education for under-sevens.
First Minister Carwyn Jones said Welsh should be promoted more as a vocational skill than an academic subject.
Ms Jones, a regional AM for South West Wales, told the Senedd on Tuesday: "It has been compulsory for every school child in Wales to learn Welsh since 1999.
"Yet despite this the numbers of Welsh speakers has fallen," she said, adding that she was learning Welsh herself.
"Polls suggest that the majority of people are opposed to compulsory teaching," Ms Jones claimed.
"Is it time that we accepted that maybe the 'stick' approach is not working and, rather than dictating everyone should learn Welsh, can we maybe instead be making it easier for those who really want to learn?"
In response, the first minister said there were "practical issues" with the idea of making all primary schools Welsh-medium in terms of recruiting teachers.
But he added: "I firmly believe it's right that our national languages should be compulsory until the age of 16.
"There are issues about the way in which Welsh has been taught in English-medium schools, particularly for the short course.
"I don't think we can say hand-on-heart that we have created confident Welsh speakers in our English-medium schools.
"Clearly that's not the case, which is why the new curriculum will be important, and which is why we're be moving away from the idea that Welsh is solely an academic area of study, moving more towards it being seen as a vocational skill."
Mr Jones said Welsh would still be available for those who wanted to study it academically, but he felt the vocational path would be "a good way of improving the way Welsh is taught and learned in the English-medium schools".
Compulsory Welsh lessons in school are not working, a UKIP AM has claimed, calling for a more voluntary approach.