The phrase 'unsuitable to be' is correct and usable in written English.
You can use it to express something not being appropriate or suitable for a certain situation. For example, "The idea is unsuitable to be used in a professional environment."
The Canadian economy increasingly requires, however, the kinds of immigrants that Canadian immigration rules deem socially unsuitable to be citizens.
As if such a marriage were grist for a news feature but unsuitable to be considered among other romances".
Teaching unions said her lack of frontline training in teaching made her unsuitable to be inspecting schools.
The campaigners say that Lambert's past work for the Metropolitan Police's undercover unit, the Special Demonstration Squad, makes him unsuitable to be employed by the university.
Others complained that the ad was unsuitable to be seen by children and might cause distress to people who had been victims of abuse.
In the foreground were three mass graves, containing the bodies of an estimated 150 Yazidi women, whom Isis forces had deemed unsuitable to be enslaved when they rampaged into Sinjar from Ba'ej and Billij in August 2014.
Well-drained soils may render unsuitable water to be fairly usable.
Donors in one Red Cross region who are found unsuitable are supposed to be listed in a donor-deferral registry.
However, Labour committee member John Mann MP said: "These actions are more proof of just how totally unsuitable he is to be a member of the FPC.
The story begins by describing how Helen Turrell's nephew, born of an unsuitable union, came to be in her care.
The team say their work could enable livers which are deemed unsuitable for transplant to be used as scaffolds.
