How to say what is necessary is just to read the book, when free. in Japanese
1)
そのその(sono) (n,n-suf) that/garden/orchard/park/plantation/place/location本本(hon) (n) book/volume/script/this/present/main/head/real/regular/counter for long cylindrical things/counter for films, tv shows, etc./counter for goals, home runs, etc.はは(ha) (int) indicating a subject/yes/indeed/well/ha!/what?/huh?/sigh暇暇(hima) (adj-na,n) spare time/free time/leisure/time off/day off/vacation/holiday/leave/quitting/firing someone/divorcing/leaving/departingなな(na) (prt) connects adj to noun/indicates emotion or emphasis/command/prohibition時に時に(tokini) (exp) by the way/incidentally/sometimes/occasionally読めno dictionary result, likely a conjigated verbno dictionary result, likely a conjigated verbばいいですよno dictionary result, likely a conjigated verbno dictionary result, likely a conjigated verb。。(。) Japanese period "."
丁寧語 (Polite form)Polite form (teineigo) convays a sense of politeness, used when speaking to strangers, people older than you, higher social status ect. Click for examples / more info
