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.

Understanding the parts of speech is very important for studying a language. It helps you understand and talk about grammar and language. It also helps for putting language together. To be a good learner, make sure you know the parts of speech.