Item showd in gstr3b but not in gstr1 how to show in gstr9

With regarding filing up of Form GSTR9 I have some of following queries:-

1. If we have showed transaction in GSTR3B of January 2018 but forget to show in GSTR1 than how to show in GSTR9? 

2. For above mentioned transaction how to show in GSTR1? Assessee files GSTR1 quarterly?

3. In part ii where it asked supplies made during year should it be considered only GST period supplies or 1.4.17 to 31.03.18?

4. While filing GSTR3B if we have sale return and issued credit note  and no other sale made  for that month how to show the reverse of output gst on account of sale return? should it clubbed with ITC of that month? Negative figures are not accepting in GSTR3B