The perfect aspect is used to talk about an action that happened before a focus time. The focus time can be past, present or future. The action is connected to the focus time. So, the perfect aspect tells us that the focus time is like this because of something that happened before.

An example

In the present perfect, we are saying that now is different because of something that happened sometime before.

I have eaten lunch.

To know the difference between "boring" or "bored", or "interesting" and "interested", it helps if you know the reasons for the difference. One comes from grammar: the past participle (PP) (VERB+ED/過去分詞) and one comes from the present participle (VERB+ING/現在分詞). So one way to understand the difference is to think about the grammar roots. But there are other ways:

• You can see the difference; 
• You can feel the difference; 
• You can understand the difference;
• You can learn by examples.

Participles are made from verbs. In English there are two - the present participle and the past participle (P.P).

The Present Participle

The present participle is made the following way:

[VERB]+ing