他一定是瘋了才會在冬天爬山。

He must have been crazy to climb the mountain in winter.

Source: Tatoeba

Sentence Composition

1
  1. (third-person singular) (since the early 20th century, usu. male) he; him; his
  2. (bound form) other; another; some other (as in 他日 and 他人 rén)
2 一定 dìng
  1. surely
  2. certainly
  3. necessarily
  4. fixed
  5. a certain (extent etc)
  6. given
  7. particular
  8. must
=3 shì
  1. to be (followed by substantives only)
  2. correct; right; true
  3. (respectful acknowledgement of a command) very well
  4. (adverb for emphatic assertion)
=3 shì variant of shì
4 fēng
  1. insane
  2. mad
  3. wild
=5 le
  1. (completed action marker)
  2. (modal particle indicating change of state, situation now)
  3. (modal particle intensifying preceding clause)
=5 liǎo
  1. to finish
  2. (used with or after a verb to express (im)possibility, as in 忘不了 wàngbuliǎo "cannot forget")
  3. (literary) (usually followed by a negative such as or ) completely (not); entirely (not); (not) in the least
  4. to understand clearly (variant of liǎo)
=5 liǎo
  1. (of eyes) bright
  2. clear-sighted
  3. to understand clearly
=5 liào unofficial variant of liào
=6 cái
  1. ability; talent
  2. sb of a certain type
  3. a capable individual
  4. then and only then
  5. just now
  6. (before an expression of quantity) only
=6 cái
  1. (variant of cái) just now
  2. (variant of cái) (before an expression of quantity) only
=7 huì
  1. can; to have the skill; to know how to
  2. to be likely to; to be sure to
  3. to meet; to get together
  4. meeting; gathering
  5. (suffix) union; group; association
  6. (bound form) a moment (Taiwan pr. huǐ)
=7 kuài (bound form) to reckon accounts
=7 kuò only used in 會撮会撮
8 zài
  1. to exist; to be alive
  2. (of sb or sth) to be (located) at
  3. (used before a verb to indicate an action in progress)
9 冬天 dōngtiān winter

classifier:

10 爬山 shān to go for a hike (esp. in the hills or mountains)