请问英语定语什么时候用词组,什么时候用分词短语?
比如这两句：
1：不用分词
The kinds of decisions they can make are.
"they can make"是"decisions"的定语
2：用过去分词
They can solve problems for people by carrying out instructions given to them.
“given to them”是“instructions” 的定语
3：用ing分词
A sequence of instructions describing how to perform a certain task is called program.
“describing how to perform a certain task”是“instructions”的定语
为什么呢?什么情况下作定语不用分词,像1句那样.什么情况下用分词,像2,3句那样.
希望得到详解