- involve - to have someone/something as part of a process or purposeful act. (implies an active role) - contain - to hold or include something as a fully enclosed or controlled entity. (physical relationship) - include - to have something/someone loosely as a part or member. (most general - may be physical or conceptual) - comprise - to include something as a constituent and often integral part. (the parts and the whole are not separable) Examples: - This project involves many people from other departments. (they play a role) - This glass contains water. (wholly enclosed volume-wise) - The package includes the computer, program, disks, and a manual. (they loosely make up the package) - The Soviet Union comprised several socialist republics. (the republics were themselves the Soviet Union)

Thanks a lot, Tony

It’s a very broad and difficult question to answer. When people learn to use words in their native language they learn through examples, not by reading and remembering definitions of them. I suggest that you use a learner’s dictionary, like Oxford Learner’s Dictionaries ( http://www.oxfordlearnersdictionaries.com/ ) Look up the different words, read the definitions and look at the examples of how the words are used. If you then still don’t understand how to use the words, then you could yourself construct natural and realistic sentences with these words and ask if you did it correctly.