Does one read 行【い】った or 行【おこな】った? In this sentence... _The policeman followed him because of his suspicious behavior._ ...does the verb mean "went" or "did" ? I found a similar example sentence in wwwjdic, but without the at the end: _The policeman followed him._

This would be , not . The latter is used to say something was carried out/executed.

Here, is actually part of the format of . When you add to a -form of a verb, it is as if the verb is currently being acted out.

> In your example, the police were likely to begin a process of following him. To say, the police began to actively follow him. It conveys a sense of progression of some event.

The other used of a directional verb you will see is , which is to say some verb arrived at something, or that something was done, and arrived at that state.

> would be something became fat after some process, to say it arrived at being fat.