a)

We use 'to-infinitive' to when we want to show purpose. We also use it after some verbs (for example agree, advise, seem, would like), after 'too' or 'enough', and in some expressions (for example to be honest, to sum up, to begin with).

(Bezokolicznika z to używamy, żeby wyrazić cel. Używamy go też po niektórych czasownikach (np. agree, advise, seem, would like), po too lub enough oraz w niektórych wyrażeniach (np. to be honest, to sum up, to begin with).)