What suffix would you use to describe a person who studies a specific field?

The suffix that indicates a person who studies a specific field is “-ologist.” This suffix is derived from the Greek word "logos," meaning "study" or "discourse." For instance, a biologist studies biology, while a psychologist studies psychology. The use of “-ologist” clearly denotes expertise in a particular area of academic or professional inquiry.

The other suffixes have different meanings: “-path” often refers to one who has a particular suffering or disease, as seen in "empath" or "neuropath," implying a connection to feelings or conditions rather than a field of study. “-iatrist” denotes a medical professional or specialist, as in "psychiatrist," who diagnoses and treats mental illness, suggesting a focus on practice rather than study. Lastly, “-ic” is a general adjectival suffix used to form adjectives meaning "pertaining to" or "relating to," but it does not specify an individual who studies a particular subject. Therefore, “-ologist” is the appropriate choice for someone who studies a particular field.