Task 4 Find and correct 1 mistake in each sentence (1,5×10=15). 1. When Mum will come, children will go for a walk. 2. He made me to work in the garden. 3. Who did play tennis? 4. I haven't never fired a pistol. 5. As an old friend, may I give you an advice? 6. You had better to prepare for the exam. 7. Nile is the longest river in the world. 8. Must I to come on time? 9. I love listen to music. 10. The museum guard asked the visitors to not touch the exhibits.

Solution:

• 1. When Mum comes, children will go for a walk. (After 'when', 'until', 'as soon as' in time clauses we use Present Simple for future events).
• 2. He made me work in the garden. (The verb 'make' is followed by the bare infinitive).
• 3. Who played tennis? (In the past simple with 'who' as the subject, we use the past simple tense, not 'did').
• 4. I have never fired a pistol. (Double negatives are avoided. 'Haven't never' should be 'have never' or 'haven't ever').
• 5. As an old friend, may I give you some advice? ('Advice' is an uncountable noun and cannot be used with 'an'. 'Some advice' or 'a piece of advice' is correct).
• 6. You had better prepare for the exam. ('Had better' is followed by the bare infinitive).
• 7. The Nile is the longest river in the world. (Proper nouns like 'Nile' referring to unique geographical features usually take the definite article 'the').
• 8. Must I come on time? ('Must' is followed by the bare infinitive, so 'to' is removed).
• 9. I love listening to music. ('Love' followed by a gerund or infinitive. 'Listening' is preferred here).
• 10. The museum guard asked the visitors not to touch the exhibits. (The structure 'ask someone to do something' requires 'to' before the verb. For negative commands, it's 'not to do something').

Answer: Corrected sentences are provided above.