The move will make it the first Scottish authority to offer all-through modern language provision - a response to the report four years ago by James McVittie, headteacher of St Ninian's High, which recommended moving the focus of language teaching further down primary and ending compulsory languages beyond S2.
From 2002-03, all council pre-five establishments have offered elementary French to children in their pre-school year, with nursery teachers receiving training to use resources adapted from the La Jolie Ronde set of materials.
French language assistants have nursery and primary classes included in their timetable, so that pre-fives receive an hour a week. In addition, nursery teachers introduce basic French vocabulary into the children's daily routine - from "bonjour" on arrival to "Ca va?" as the day progresses and everything from "des pommes" to "des bananes" at snack time.
Margaret Grant, a nursery teacher at Glenwood nursery in Thornliebank, who started teaching in 1965, said: "I did Higher French but in my day it was all the writing and reading of French. We really didn't speak it very much.
I could read it out loud but to understand someone speaking to me was very difficult - I didn't have much experience of that."
Her confidence grew after doing continuing professional development with Elaine Pasternak, East Renfrewshire's staff tutor in modern languages - a former secondary modern languages teacher who retrained to teach languages in primary and nursery.
"The first year I went for six afternoons of training with Elaine and thereafter once a month for the rest of that year and all the next year," she says. "This year I have had a French assistant. The first year I had a French assistant for five or six weeks coming an hour a week and last year I did it myself. This year my assistant is from Quebec. I sometimes sit in with her but we try to incorporate French into the lessons every day - things like "Quel temps fait-il?"
She added: "The children enjoy it very much. Some of them don't seem to respond greatly but then they go home and tell their parents about the things they have been doing.
"I was a bit nervous when I started but Elaine Pasternak came in one day after a few weeks and did a little lesson with a puppet. After that I could see exactly what was to be done and we have materials to help us. I think it's very worthwhile - the earlier you start teaching languages the better."
Mrs Pasternak said that children from pre-five to P2 learnt French through speaking and listening but when they enter P3 next year they will begin reading and writing - skills which are developed through to P7.
To date, the most ambitious primary modern language initiative has been the immersion programme in French at Walker Road primary in Aberdeen, but the difficulty there was finding primary-trained teachers who were completely bilingual.
"This programme is sustainable and we are finding that a lot of primary teachers are using our training to fulfil their CPD requirements," Mrs Pasternak said.
East Renfrewshire has divided its CPD training in French into two formats - infant training, offering the methodologies and vocabulary required for pre-five to P3, which is made up of eight two-and-a-half hour sessions after school; and full MLPS (Modern Languages for the Primary School), where the authority asks primary schools to release teachers who have done Higher French for a 15-day block which incorporates infants' French.
Some 60 per cent of pre-school and primary teachers have undertaken one of these formats.
While pupils who started French in pre-school are still only in P2, a ripple effect is being felt. "We have noticed that older children in the school with younger siblings are amazed at what their young brothers and sisters can say. The young children are very positive about doing French, very enthusiastic," Mrs Pasternak said.
"A lot of teachers are including French when their class is asked to take the school assembly, so they are choosing songs and activities in French from the core resources to perform in front of the whole school."