What do you need to know so things are not  

foggy and  scary  anymore, but cristal clear?

Do read the information from Grammar, verbs, book 1   Verbs in English. 

1 The present and past forms of the verbs BE and have:

am/is/are/was/were/been and  have/has/had.

2 The rules for the simple aspect of each tense.

3 Keep in mind that the main verb has the SAME form for all the persons in a certain tense.

4 Only the helping verb changes according to the tense and person.

5 Each aspect has a specific helping verb: "be" goes with the continuous and "have" with the perfect aspect. 

Present simple: 

S + vb (s,es)

Present continuous goes with the helping verb be in the present tense and the main verb in the  -ing form. Remember that only the hepling verb changes its form.

S + am/is/are + vbing

Here are some examples:

l am studying right now.

You and they are learning at the moment.

She is creating a book for her students now.

We are waiting for the results.                                                     

Past simple:           S+vb2

Past continuous goes with the helping verb be in the past tense and the main verb in the  -ing form. Remember that only the hepling verb changes its form.

S + was/were+vbing

Here are some exapmples:                                                        

I was writing an e-mail when my mum called.

He was exaplaing the rules to his younger brother.

We were planning our holiday when we heard that it was cancelled.                                                                                

Present perfect simple:       S+have/has+vb3

Present perfect continuous has two auxiliary verbs,  have and be, as it is a combination of two aspects. The main verb has the -ing form and does not change. So, the helping verb be is used in the present perfect tense.

S+ have/has been+vbing

Here are some examples:

I have been waiting for this book for 3 years.

They have been learning Spanish for one month.

She has been reading for 5 hours. It must be an interesting book!

Past perfect simple:       S+had+vb3

Past perfect continuous has two auxiliary verbs,  have and be, as it is a combination of two aspects. The main verb has the -ing form and does not change. So, the helping verb be is used in the past perfect tense.

S+ had been+vbing

Here are some examples:

I had been cleaning for 30 minutes before he arrived.

They had been learning Spanish for one month, then they went to Madrid.

She has been reading for 5 hours. It must be an interesting book!

Future simple:       S+will+vb1

Future continuous has two auxiliary verbs,  will and be. The main verb has the -ing form and does not change. So, the helping verb be is used in the Future tense.

S+ will be+vbing

Here are some examples:

I will be reading at 3 pm tomorrow.

They will be learning Chinese this time next week.

Future perfect simple:       S+will have+vb3

Future perfect continuous has three auxiliary verbs,  will, have and be. The main verb has the -ing form and does not change. So, the helping verb be is used in the future perfect tense.

S+ will have  been+vbing

Here are some examples:

I will have been reading this book thrice before l will return it to the library. l need to understad its message well.