What's the difference between" the topics discussed" and "the discussed topics"?

As a non-native speaker, I think those two above mentioned has no difference. If any, would any of you tell me the subtle difference? As far as I am concerned, past participles should be put before nouns except for past participle phrases modifying nouns.

Solution 1:

The difference between "discussed topics" and "topics discussed" depends on how the two words are positioned in the overall text.

English is a spoken language. Rhythm and emphasis have meaning. However, sometimes this is hard to represent in written form, especially for non-native speakers, who may not "hear the words in their heads" as the writer originally imagined them.

English is very flexible in its word placement, and this makes it possible for the writer with a sense of rhythm to place the most important word at a point in the sentence where the emphasis would be natural.

For example, imagine someone attending a meeting on global warming, and describing the experience to a friend:

• Well, the discussed topics were all about agriculture. No one seemed to care about the fishery at all. Our group couldn't even get on the agenda. versus,

• Well, the topics discussed were pretty technical, but all the parties had tables in the hallways, and there were always people standing around them.

In the first case, the sense is that there were some topics discussed and some topics not discussed. The speaker wants to emphasize this before moving on to the next thought.

In the second case, the sense is that the topics had some common property, but that their discussion is less important.

There is no written grammatical rule to guide you on this, in part because the violation of conventional phrasing is often used to create a more memorable phrase.

To improve your ear, you could try Vital Speeches of the Day. It takes a little work to find the best examples, but in each case you are looking at words that were meant to be spoken aloud, written by people with a good sense of the language. The printed speeches are speeches printed, if you get my drift.