5-05. three, three of.
[There are three things here.] = There are two things here, and there is one more thing here.
[I see three people.]
5-06. four, four of.
[There are four things here.] = There are two things here, and there are two more things here.
[I see four big animals.]
5-07. five, five of.
[There are five things here.] = There are four things here, and there is one more thing here.
[I see five small animals.]
5-08. group, groups, group of, groups of.
[X is a group of things.] = There are two or more things in a place, but you think about them like they are one thing. You think like this: X is one thing, and these two or more things are like parts of X or like things inside X.
[A group of big animals moved towards me.]
[This group contains the machines that someone damaged.]