"exert great efforts" is correct and can be used in written English.
It is used when you want to emphasize a considerable amount of effort and energy being put into something. For example: "In order to pass the exam, John exerted great efforts in preparing and studying."
"You do not need to exert great effort or spend a lot of money to make 10g of explosives, more or less.
Maybe this was Dell's plan all along: let other companies exert great effort in chipping away a foothold in the iPad mountain.
I needed to exert great effort simply to project my voice, and for decades I had to catch my breath after speaking just five or six words.
Similarly, effort expectancy may not have a significant relationship with behavioural intention because people tend not to exert great effort during a pilot project.
The entire Ukrainian people was exerting great efforts .
Finally, it is fair in that it does not penalize those who invest in education and exert greater effort.
Individuals with CFS appear to have to exert greater effort to process auditory information as effectively as demographically similar healthy adults.
Mills (2014) explained the importance of SE: Students with high self-efficacy to perform academic tasks tend to exhibit lower levels of anxiety, display increased persistence when faced with obstacles, exert greater effort, show more flexible learning strategy use, and display higher levels of intrinsic interest in academic tasks.
If an agent were disposed to exert greater effort if necessary, we would, I think, attach less significance to the low level of effort that was actually expended.
According to Weiner, the workforce is more likely to initiate change, exert greater effort, exhibit greater persistence and cooperate better when organizational readiness for change is high [ 19].
