expertise

The word “expertise” means specialized skill or deep knowledge in a particular area. In plain terms, the know-how someone has built up in a specific field.

“Expertise” is pronounced ehks-pur-TEEZ (/ˌɛkspɚˈtis/ in IPA).

Here is “expertise” used in a sentence: “The firm hired her for her expertise in tax law.”

“Expertise” is a noun.

The word “expertise” comes from French. Borrowed from French expertise, built from expert.

“Expertise” is a fairly common word in modern English.

Experience is what you have done or lived through; expertise is the specialized skill or deep knowledge that doing it well produces. Years of experience usually build expertise, but the words are not interchangeable — someone can have long experience in a job without developing real expertise, and expertise is always tied to a particular area.

No. Expertise is an uncountable noun, so it has no plural and does not take "a" or a number. When you need to talk about more than one field, use phrases such as "areas of expertise" or "fields of expertise": "The team covers several areas of expertise."

The standard preposition is in: "expertise in data analysis," "expertise in tax law." On occasionally appears with topics of knowledge, but in is the safe, idiomatic choice in almost every context. To credit people, use of: "the expertise of our engineers."

A skill is the ability to do a particular thing well, and it can be narrow and practical — typing is a skill. Expertise is broader and deeper: specialized skill or knowledge covering a whole area, usually gained over time. Skills can be listed one by one; expertise describes command of a field.