The phrase "a major change when" is correct and usable in written English.
It can be used to introduce a significant alteration or transformation that occurs at a specific time or under certain conditions.
Example: "There was a major change when the company decided to implement remote work policies."
Alternatives: "a significant shift when" or "a substantial alteration when".
Like two distant streetlights, one inside a fog bank and one outside, the quasars appear different when observed with powerful telescopes, apparently confirming that the universe went through a major change when it was about 900 million years old.
When frontline employees are anticipating a major change, when they are becoming increasingly tense and worried, when their blood is beginning to run hot, the last thing you should do is gather them into a large group.
Post offices may not have much of a future, at least as services distinct from the general industry of getting of things from A to B, but again it's easier to explain a major change when you start from something familiar, so here goes.
West Bengal politics underwent a major change when the Left Front won the 1977 assembly election, defeating the incumbent Indian National Congress.
But you know it's time to make a major change when you wake up most days and dread going to work.
But in the November midterm elections, the Democratic Party signaled a major change when it flipped the GOP's four House seats to sweep six of seven districts in the county.
While this latest guidance is only the final draft version, there tends not to be any major changes when the official recommendations are published - normally a few months after this stage.
Times and attitudes may have moved on but I don't quite see that translating into major change when it comes to the crunch on polling day especially in such a tight contest".
In our studies of managers, we have found that the difference between those who take the initiative and those who do not becomes particularly evident during phases of major change, when managerial work becomes relatively chaotic and unstructured.
But at certain points in one's career -- especially in the beginning, when you are contemplating a major change, and when you are thinking of leaving the workforce all together -- multiple mentors can bring together different yet valuable perspectives, cautionary tales and encouragement.
You're astonished that you could have ever missed such a major change, especially when you've been staring mesmerized by this tableau for 20 minutes.
