湯姆和瑪麗不知道他們應該去哪兒。

Tom and Mary didn't know where they should go.

Tom and Mary didn't know where to go.

Source: Tatoeba

Sentence Composition

1 湯姆 Tāng Tom (name)
=2 old variant of
=2 surname He
=2
  1. (joining two nouns) and; together with; with (Taiwan pr. hàn)
  2. (math.) sum
  3. to make peace
  4. (sports) to draw; to tie
  5. (bound form) harmonious
  6. (bound form) Japan; Japanese
=2
  1. to compose a poem in reply (to sb's poem) using the same rhyme sequence
  2. to join in the singing
  3. to chime in with others
=2 to complete a set in mahjong or playing cards
=2 huó
  1. to combine a powdery substance (flour, plaster etc) with water
  2. Taiwan pr. huò
=2 huò
  1. to mix (ingredients) together
  2. to blend
  3. classifier for rinses of clothes
  4. classifier for boilings of medicinal herbs
=2 (literary) harmonious (variant of )
=2 huo
  1. (obsolete on its own in Standard Chinese) warm
  2. warm
3 瑪麗
  1. Mary or Marie (name)
  2. Mali
4 不知 zhī
  1. not to know
  2. unaware
  3. unknowingly
  4. fig. not to admit (defeat, hardships, tiredness etc)
=5 dào
  1. (bound form) way; reason; principle
  2. (bound form) a skill; an art; a specialization
  3. (Daoism) the Way; the Dao
  4. to say (introducing a direct quotation, as in a novel)
  5. (bound form) to express; to extend (polite words)
  6. classifier for long thin things (rivers, cracks, shadows etc), barriers (walls, doors etc), questions (in an exam etc), commands, courses in a meal, steps in a process
  7. (old) circuit (administrative division)

classifiers: ,

=5 dǎo
  1. (obsolete on its own in Standard Chinese) alternative form of / (dǎo, “to direct; to guide; to lead; to conduct”)
  2. alternative form of / (dǎo, “to direct; to guide; to lead; to conduct”)
6 他們 men they; them
7 應該 yīnggāi ought to; should; must
8
  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)
9 哪兒 r
  1. where?
  2. wherever; anywhere; somewhere
  3. (used in rhetorical questions) how can ...?; how could ...?