To specify the condition and its effect we use the “If-then” structure in English

e.g. 1) If you had gone then I would have gone as well.
Had he eaten well you he would have become healthier.

For If-then in Marathi, we use जर- तर (jar- tar )

The past perfect tense is used as a base for such a sentence.

Sentence formation

The form of असणे(“asaNe”) are mentioned below :

He opened the door -> त्याने दार उघडले (tyAne dAr ughaDale)
If he had opened the door then -> त्याने दार उघडले असते तर ( tyAne dAr ughaDale asate tar )

He had spoken -> तो बोलला होता (to bolalA hotA)
If he had spoken -> तो बोलला असता तर (to bolalA asatA tar)

The base of the sentence is “past perfect tense”. As we had seen before, “past perfect tense” has two types.
1) verb with objective
2) verbs without objective

So the same can be seen here. For the first type, the form of verb and form of asane depends on gender and multiplicity of the object.
e.g.
The door is neuter-singular. So we used “उघडले असते”
If we wanted to use the window instead of door. Then sentence would be: त्याने खिडकी उघडली असती तर (tyAne khiDakI ughaDalI asatI tar)
“खिडकी” is feminine-singular so we used “उघडली असती”

In another type of sentence, the verb depends on the doer.
e.g.
If he had spoken -> तो बोलला असता तर (to bolalA asatA tar)
Here verb does not have an object. The doer is “He”. So we used “बोलला असता”

The second half part of the sentence ( i.e. after “then” ) will also be formed the same way

e.g.
If you had spoken then she would have spoken. -> जर तू बोलला असतास तर ती बोलली असती (jar tU bolalA asatAs tar tI bolalI asatI )
If he had cried then they ( plural of it ) would have ran -> जर तो रडला असता तर ते धावले असते (jar to raDalA asatA tar te dhavale asate)

“If-Then” structure can be used to predict the future also. i.e. to indicate what will be the effect if some action is taken.
e.g.
If you go I will cry.
If he studies he will be happy.

In Marathi, for condition part “simple past tense” is used. And for effect part “future tense” is used.

Structure is:
जर condition part in simple past तर effect part in the future tense

Example:
1) If you go I will cry.
Condition is “you go”. It simple past tense is “you went” which in Marathi is तू गेलास ( tU gelAs )
Effect part is “I will cry” which in Marathi is मी रडेन (mI raDen)
So finally the whole sentence is Marathi becomes
जर तू गेलास तर मी रडेन ( jar tU gelAs tar mI raDen )

2) If he sings she will dance.
Condition is “he sings”. It simple past tense is “he sang” which in Marathi is तो गायला (to gAyalA)
Effect part is “she will dance” which in Marathi is ती नाचेल (tI nAchel)
So effectively the whole sentence is Marathi becomes
तो गायला तर ती नाचेल ( to gAyalA tar tI nAchel )

Try creating sentences with different verbs using above rules. Crosscheck them by creating same by “verb forms” feature on https://learnmarathiwithkaushik.com/