Endless Questions

I have found 2 different plurals, plus one dual for the word for bathroom. I'm ok with the dual, but why is there one masculine and one feminine plural? This is all on one page of my text book. I can live without the answer, but am curious.

حمام

حمامان

حمامين
حمامات

Please comment below if you know the answer.

قبل اسبوعين حضرت محاضرة

Article from Al Monitor com on the destruction and illegal trade of artefacts in the Middle East. The RCSS held a meeting in Yemen, UNESCO released a report and another meeting was held in Paris by the Experts Meeting on the Safeguarding of Yemen's Cultural Heritage.

3 lectures in a row on this topic at the Ashmolean Museum on Saturday 25th July.

قبل اسبوعين حضرت  محاضرة عن الدمار على مدينتان الموصل والنمرود, في المتحف اشموليان في اكسفورد

Vocab:

حضرت - I attended

محاضرة - a lecture

الدمار - the destruction