Here in this formation S indicates the subject,V indicates the verb and the number 1 indicate the verb form and then O indicates the object in a sentense.
Examples
I eat rice.
I go.
He goes.
(Important information)
If subject is 3rd person singular in this tense than +s/es add on verb.so there is he+go+es in examples.
Present continuous
Formation of present continuous tense
(S+am/is/are+v+ing+o)
Examples-
I am going.
He is doing.
They are playing.
Present perfect tense
Formation of present perfect
(S+have/has+verb 3rd form+o)
Verb 3rd form means-past participle of verb.
Examples
I have done this work.
He has gone there.
Present perfect continuous tense
Formation of present perfect continuous
(S+has been/have been+v+ing+o)
Examples
I have been playing cards.
He has been doing this sum.
2.Past Indefinite/Simple Past tense
Formation of simple past
(S+v2+o)
Here verb 2 indicates the 2nd form of a verb in english.