please suggest study material and papers for st olaves focused study

The practice materials listed on this page will be helpful to your DS: https://www.elevenplusexams.co.uk/schoo ... ey-11-plus

St Olaves is exceptionally competitive. Techniques on timing and accuracy will be helpful too.

What year is your DS? if he is not yet in Y5 you might want to consider just keeping him well focused on good Maths and English studies, reading widely and encouraging a bit of story writing or comprehension work if he doesn't do much at school rather than add too much too early.

St Olaves PTA also run mock tests which would be good to look out for.

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