a crucial role — play/have a crucial role (in something)
collocationC1IELTS 7+neutralcommon
to be an extremely important or decisive part of a situation, process, or outcome; to have a major influence on what happens.
Say it like a native
Textbook Mentors fulfil an indispensable function in a child's development.
Native Mentors play a crucial role in a child's development.
'Play a crucial role' is the natural collocation; 'fulfil an indispensable function' is bureaucratic.
Pattern: play/have a crucial role (in + noun/gerund)
In use
- Parents play a crucial role in shaping their children's values and attitudes.daily life
- In my opinion, government support plays a crucial role in improving public health, because without sufficient funding, many essential services would not be available.IELTS speaking
Common mistake
✗ She has a crucial role for the team's success.
✓ She plays a crucial role in the team's success.
You 'play a crucial role IN' something — not 'for'.
Common collocations
play a crucial role + in— a crucial role, a key role, in the process, a vital role
Don't confuse it
At B1/B2, learners may use 'an important role' or 'a big part', but 'a crucial role' is more emphatic and suggests that without this person or thing, the outcome would be very different.