Present Continuous Tenses are used when describing a particular point in time. In the Present Continuous Tense we are discussing something that is happening now. We add the suffix –ing to the word stem to create examples like the following.
Present Perfect Continuous Tenses are used to describe something that has been occurring up until this point (and/or is still occurring,) and to describe the length of time that something has been occurring up until this point.
Past Continuous Tenses are used to describe a past action that occurred over a period of time.
The Past Perfect Continuous refers to longer situations that occurred up until the moment in the past we are discussing, and can describe the length of time they occurred for.
The Future Continuous Tense is used for certain specific future arrangements and plans.
Hopefully this has added some clarity to your understanding of the Continuous Tenses. As you practise them with different verbs and in various contexts, your use of the English Grammar Tenses will grow.