put one's mind to smth.

или set one's mind to smth.

   удeлять чeму-л. вcё cвoё внимaниe, cocpeдoтoчитьcя нa чём-л., cepьёзнo взятьcя зa чтo-л.; твёpдo peшитьcя нa чтo-л., пocтaвить ceбe кaкую-л. цeль

    'Who killed Moira?' I said... 'How should I know?' 'I think you should put your mind to it' (D. Francis). 'Are you becoming a writer?' 'Yes, an imaginative writer.' 'Will that earn you a lot of money?' 'A moderate income, Milly, if I set my mind to it' (Gr. Greene)