我以為地鐵是免費的，所以我沒買票就去了。

I thought that the metro was free, so I went without a ticket.

Source: Tatoeba

Sentence Composition

1 我 wǒ
  1. I
  2. me
  3. my
2 以為 yǐwéi to think; to believe (often with the implication that the belief is mistaken – unless referring to one's own current belief)
3 地鐵 dìtiě
  1. underground railway; subway
  2. subway train
=4 是 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)
=4 是 shì variant of 是 shì
5 免費 miǎnfèi free (of charge)
=6 的 de
  1. of; ~'s (possessive particle)
  2. (used after an attribute when it modifies a noun)
  3. (used at the end of a declarative sentence for emphasis)
  4. (used after a noun, verb or adjective to form a nominal expression, as in 皮革的 pígéde "one made of leather" or 跑堂兒的 pǎotángrde "a waiter (literally, one who runs back and forth in a restaurant)" or 新的 xīnde "new one")
  5. also pr. dì or di in poetry and songs
=6 的 dī a taxi; a cab (abbr. for 的士 dīshì)
=6 的 dí really and truly
=6 的 dì (bound form) bull's-eye; target
7 所以 suǒyǐ
  1. therefore
  2. as a result
  3. so
  4. the reason why
8 我 wǒ
  1. I
  2. me
  3. my
=9 沒 méi (negative prefix for verbs) have not; not
=9 沒 mò
  1. drowned
  2. to end
  3. to die
  4. to inundate
10 買票 mǎipiào
  1. to buy tickets
  2. (Tw) to buy votes (in an election)
11 就 jiù
  1. (after a suppositional clause) in that case; then
  2. (after a clause of action) as soon as; immediately after
  3. (same as 就是 jiùshì) merely; nothing else but; simply; just; precisely; exactly
  4. only; as little as
  5. as much as; as many as
  6. to approach; to move towards
  7. to undertake; to engage in
  8. (often followed by 著 zhe) taking advantage of
  9. (of food) to go with
  10. with regard to; concerning
  11. (pattern: 就 jiù ... 也 yě ...) even if ... still ...
  12. (pattern: 不 bù ... 就 jiù ...) if not ... then must be ...
12 去 qù
  1. to go
  2. to go to (a place)
  3. (of a time etc) last
  4. just passed
  5. to send
  6. to remove
  7. to get rid of
  8. to reduce
  9. to be apart from in space or time
  10. to die (euphemism)
  11. to play (a part)
  12. (when used either before or after a verb) to go in order to do sth
  13. (after a verb of motion indicates movement away from the speaker)
  14. (used after certain verbs to indicate detachment or separation)
=13 了 le
  1. (completed action marker)
  2. (modal particle indicating change of state, situation now)
  3. (modal particle intensifying preceding clause)
=13 了 liǎo
  1. to finish
  2. (used with 得 dé or 不 bù after a verb to express (im)possibility, as in 忘不了 wàngbuliǎo "cannot forget")
  3. (literary) (usually followed by a negative such as 無 wú or 不 bù) completely (not); entirely (not); (not) in the least
  4. to understand clearly (variant of 瞭 liǎo)
=13 了 liǎo
  1. (of eyes) bright
  2. clear-sighted
  3. to understand clearly
=13 了 liào unofficial variant of 瞭 liào