worthwhile 用於下列句型：
It is worthwhile doing sth./ to do sth.幹某事是值得的
但不能說：sth.is worthwhile doing/ to do
長城值得去旅遊.It is worthwhile visiting/ to visit the Great Wall.
worth 用於下列句型：sth.is worth sth/ doing
此句型中只能用doing,不能使用被動.
The museum is certainly worth a visit.=The museum is certainly worth visiting.
這個博物館的確值得參觀.
This idea is well worth considering.這個想法很值得考慮.
worthy 用於下列句型：sth.be worthy of sth/ being done sth.be worthy to be done
這部電影值得看.The film is worthy of being seen.= The film is worthy to be seen.