Practice, part by part
Two exercises in every part are free — open one and start, no account needed until you want your results. Pick the level you are sitting; both are covered by the same pass, so you can move between them.
A Cambridge paper is not one skill, it is six or eight separate tasks wearing the same cover. Reading & Use of English alone asks you to pick a word from four, produce one from nothing, rewrite a sentence around a fixed key word, and read for gist, detail and opinion — and it is entirely normal to be comfortable with three of those and lose marks steadily on the rest. Sitting whole mock papers over and over tells you the total went up; practising part by part tells you which part moved.
That is what this section is for. There are 760 practice exercises at B2 First and 820 at C1 Advanced, filed by paper and by part, each one built to the official format and each one explained question by question. Work the parts you are weakest at until the format stops surprising you, then book yourself a full timed mock to check it holds together under the clock.
Two exercises in every Reading & Use of English, Listening and Speaking part are free and open without an account (a free one shows your results), and so is the first Writing task of each type, so you can find out what the material is like before deciding anything. The rest of the bank comes with a pass.
Not to start — the first two in every Reading & Use of English, Listening and Speaking part open straight away, with no email and no card. You need an account to see your results, keep your attempts and track your progress, and creating one is free too.
If you can finish a B2 First reading paper with time to spare and your writing loses marks for range rather than mistakes, practise C1 Advanced. If you are still guessing in the last five minutes, practise B2 First. If you genuinely cannot tell, the free fifteen-minute level test will: it uses the real exam formats and gives you a band at the end.
Both, in that order. Part practice fixes the specific task types you drop marks on; a full mock under the real clock tests something different — stamina, pacing, and whether you can still think clearly in the last ten minutes. Most candidates get the best of it by drilling parts through their preparation and sitting complete papers in the final few weeks.
