BizWritingTip reader: “Would you please help me with the difference between ‘diagnoses’ and ‘diagnosis’? Are these words singular and plural?”
BizWritingTip response: “Diagnosis” is a singular word meaning the identification of an illness or disease by means of a patient’s symptoms.
Dr. House’s diagnosis was accurate – as usual.
The word “diagnoses” is the plural form.
It took several diagnoses before his residents reached the right conclusion.
“Diagnose” can also be used as a verb, meaning to distinguish or to indentify by diagnosis.
Dr. House will diagnose the problem correctly by the end of the show.