Parts of the following sentence are given as options. Identify the segment that contains a grammatical error.

The plant will die unless you will water it every day.

The correct sentence is- 'you will water'Key Points 

• In the given sentence, the verb 'will' is incorrectly used.
• As the given sentence is a conditional sentence. So the main clause should be in the future tense and the subordinate clause will be in the present indefinite tense.
• Let's understand the structure of the conditional sentence:
  • simple future tense [main clause] + if/unless + simple present tense [subordinate clause].
    • ​​Example: I will go to the movie if I complete my homework.
• So to make the sentence correct remove the helping verb will. 
• Thus, option 1 is the correct answer.
   

And the correct sentence is: The plant will die unless you water it every day. Additional Information

• First conditional sentences are used to express situations in which the outcome is likely (but not guaranteed) to happen in the future.
  • Examples: 
  • If you rest, you will feel better.
  • If you set your mind to a goal, you’ll eventually achieve it.