The following sentence has been split into three segments. Identify the segment that contains a grammatical error. If you don’t find any error, mark ‘No error’ as your answer.

Don’t panic! / We won’t leave you alone in trouble / when you travelling with us.

The correct answer is "When you travelling with us".

Key Points

• In time clauses with words like when, after and until, we often use present tense forms to talk about the future:
• For example:
  • I'll come home when I finish work.
  • You must wait here until your father comes.
  • They are coming after they have had dinner.
• Hence, the correct sentence would be: Don't panic! We won't leave you alone in trouble when you travel with us. 

Therefore, the correct answer is "Option 1".

Additional Information

• "Don’t panic!" – This sentence is free from any grammatical mistakes.
  • It's a command or an imperative sentence and is grammatically correct.
  • The subject (you) is understood and does not need to be stated explicitly.
• "We won’t leave you alone in trouble" – This sentence is also error-free.
  • The phrase 'We won't' is a contraction for 'we will not' which is grammatically correct.
  • 'Leave' is a proper base form of the verb to use after 'will not.'
  • The rest of the sentence, 'you alone in trouble,' correctly follows standard English grammar rules.