You often have to describe obligations and choices / options in IELTS Writing Task 2 or in IELTS Writing Task 1 letters (in the General Training IELTS Test)
These 2 activities will help you to develop your knowledge of some important words and phrases to describe obligations and choices.
In the first activity, the obligation or choice word is highlighted in bold. Then read the definition underneath each sentence. Is the definition true or false?
In the second activity, complete each sentence with one of the words on the right.

Thank you sir for very helpful resources
Nice exercises to practise vocabulary! I did the IELTS Charlie course and scored 7.5 in my writing. It has really useful tips. Just want to say Thank You! Overall score was 8.5! Extremely happy