These words are alike in denoting a person empowered to take the place or position of another. Representative in its wider application means a person or thing that stands for, acts for or takes the place of another. In its narrower application, representative means a person who acts for another or other in a special capacity.

• Representatives in Parliament act for their constituent in legislative matters; Ambassadors are representatives of their country’s government who are stationed in other nation’s capital.

A substitute is a person or thing that can be used instead of another person or thing.

• Honey can be used as a substitute for sugar in may recipes; A musician who cannot appear on the bandstand because of illness, or for some other reason, customarily gets a substitute to play in his place; An understudy is an actor or actress who learns the part of leading player and stands by to assume the role in the event of sickness or misadventure: Because of the leading man’s recurring throat trouble and the likelihood of a long run, the understudy will take the part for the next month. A stand-in is not an understudy but one who relieves the star (usually in films) when he needs to be kept free from unnecessary exertion or danger, or when some particular skill is required: A stand-in was used in the duelling scene. Both these words are used informally in everyday applications: Will you stand-in for me at the dinner?; Better get an understudy (or stand-in ) for the conference if you cold gets any worse.

In general, agent means one who acts on behalf of another person or a corporate entity by authority.

• The treasurer of a club acts as its agent in financial matter; In a dictatorship, all government officials are personal agents of the dictator rather than representatives of the people.

In its more restricted sense, agent means one who acts on behalf of one of two parties.

• A real-estate agent acts on behalf of the landlord in transactions between landlord and tenant; A theatrical agent handles business with the producer for his actor-client.

A proxy is one who acts as an agent for another at a ceremony or in an election.

• Marriages by proxy occurred during World War II: if the groom was overseas, another person would act as his proxy at the ceremony; Most shareholders vote for directors by proxy ; that is, they authorize an agent to vote on their behalf.

Delegate and deputy usually refer to representatives who are closely bound by instructions; the use of the title representative rather than delegate or deputy often implies a lack of such instructions, or less binding ones. Thus a Parliamentary representative , once he is elected, may be free to vote for or against legislation as he sees fit, but a delegate to a party conference may be required to vote as his branch directs. A deputy is usually a person who acts under powers granted by a superior. The Prime Minister’s deputy has powers conferred by Parliament.