The question you raised for advice is cryptic and lacks the necessary details required for careful consideration. The term "ignorance of work" can be interpreted in different ways, such as the person being ignorant of the job knowledge and experience required for the job they have been recruited for. This might have occurred because they have been placed in a job demanding skills other than what they possess, or they have been recruited without assessing their skill/knowledge for the job in question. In both of these situations, the HR department is to blame for its inefficiency, for which the employee concerned cannot be held responsible.
In the other case, you have not clarified what the person is doing while ignoring their job, such as idling, inciting co-workers or other workers, or being absent from work, etc. Your warning letter will be ineffective if issued without these details.
Suggested Warning Letter
Dear...,
Designation: __________
Section: __________
Department: __________
It has been brought to the notice of the management that you have been ignoring your work since ________ and have been loitering while on duty. This has adversely affected production in your section and is affecting the discipline of the section. Your supervisor has advised you time and again against it but in vain.
In view of the above, you are hereby warned and advised to desist from these activities in the future. In case no improvement is found in your work and conduct in the future, the management will be compelled to take disciplinary action as it may deem fit.
HR
In case the employee comes up with a reply, please ignore.
Thanks and regards,
S.K. Johri