agar tu chahta to ye kar sakta tha.
tumhe pata tha main aane wala tha fir bhi tum chale gaye.
if you wanted you would have done this.
you were already aware that i would come still you went away from here.
If you had wished, you could do this.
You left despite you knew that i was about to come.
If you had wanted/ Had you wished, you could/would have do/done this.