While many of these are similar in form, here are some situations where one might be better than another... carry out - to follow orders that someone has given you, to follow through with plans you set for yourself, to finish something you started (it's also what you do with dinner you order and pick up from a restaurant!) conduct - to do an experiment, to lead an orchestra, to lead people through a series of organized events or directions (it is also what certain materials do to carry heat from one place to another) execute - to put a plan into effect, usually something with some importance or finality (execute the landing sequence to land the plane at the end of a flight, execute the self-distruct function on a machine). This is where the meaning "to kill" is connected - to execute someone is to plan to put a finish to their life, and then to do it. Similarly, you use execute for wills - when you die, an executor executes your will, or does the things you said should be done in your will. implement - to use something such as an item or a plan or program perform - do do a certain task, sometimes doing it while being observed and/or judged; you perform tasks at work, but you wouldn't "perform" an errand to go grocery shopping So, to put them all into one short story: Yesterday, I carried out a plan I have to solve world hunger. I started by conducting an experiment in my lab at work. I executed each stage of the experiment perfectly, and came up with the answer! If we implement my results all over the world, no one will go hungry again! If my co-workers and I continue to perform well, we might even get a raise! Hope that helps with some of the nuances in these words!

call for

In pratical terms, they are all the same. In most cases you can use any that you want. Some of these terms have alternate meanings. Execute can mean to kill. Implement can be a noun meaning some used to do something like a pencil is a writing implement. Conduct is also a noun for the way a person acts.