Plans to cut class sizes for younger pupils are to be announced by Scottish Education Secretary Fiona Hyslop.
Scottish councils are to get funding to employ 300 more pre-school and primary teachers from August in a bid to reduce class sizes, the government has said.
In the run-up to last month's election the SNP promised children in their first three years of primary would be in classes of no more than 18 pupils.
However, the SNP administration did not made a firm commitment to its manifesto pledge of keeping class sizes to no more than 18 in primary 1-3.
Ms Hyslop is expected to confirm that manifesto pledge at Holyrood later.
Education Secretary Fiona Hyslop also announced that the number of hours of free nursery education is to increase.
However the pledge had no deadline for delivery and Ms Hyslop is expected to indicate that it will not come about immediately.
She said she was determined to make Scotland a "smart learning nation."
Nursery education
The limit on class sizes in early primary is 25 and unions have called for a cap of 20 in all classrooms in Scotland.
The limit on class sizes in early primary is 25 and unions have called for a cap of 20 in all classrooms in Scotland.
The SNP party's manifesto said: "We will maintain teacher numbers in the face of falling school rolls to cut class sizes and place greater emphasis on teacher recruitment for the early years, languages and science."
The education secretary told MSPs that the government was serious about cutting class sizes, adding: "We are sorting out the problems the last government caused and are happy to do so.
It is understood that ministers believe the plan is proven to improve performance in the key early years at school.
"This government is moving fast to start delivering on class sizes."
However, the move has prompted concerns that it will make it harder to get into more popular schools unless additional classrooms are built.
She added that another 250 teachers would start training this year.
The Nationalists have also pledged to increase the provision of free nursery education for three and four-year-olds by 50%.
Ms Hyslop also told the Scottish Parliament that the entitlement for three and four-year-olds to pre-school education would be increased to 475 hours a year from the autumn.
This would see the entitlement increased from 400 hours to 600 hours.
Ms Hyslop announced plans last week to scrap the graduate endowment for Scottish students at Scottish colleges and universities.
Natural decline
In England, the Labour government has limited infant classes to 30 pupils at most.
But some believe it has missed a golden opportunity to reduce classes, because the number of young children in the population has fallen - whereas primary school teacher recruitment has risen.
The Liberal Democrats have long been calling for the demographic changes to be turned to advantage.
They have argued for maximum sizes of 20 for infants and 25 for older primary school children.
A spokesman said: "We are still also committed to funding the recruitment, training and employment of 21,000 extra primary school teachers in order to deliver classes of 20 for 5 to 7-year-olds and 25 for 7 to 11-year-olds."
