Arabic Grammar  (Genders)
Masculine (Mas.) and Feminine (Fem.) 

Most feminine singular nouns end with a round Ta (marbuta) or .  A masculine  (singular) noun may be changed into feminine (singular) by simply adding or at the end.  Exception:  those noun that are naturally a type, it is not possible to convert into other type. for example Father, Mother etc. 

Conversion (1) replace dammatain   (from last letter) with  a fathah   (2) add round ta with dammatain at the end.    Example
                                                       

small (Mas.)	small (Fem.)	big (Mas.)	big (Fem.)
uncle (an)- father side	aunt (an) -father side	uncle (an) - mother side	aunt  (an) - mother side
worshipper (a) - male	worshipper (a) female

Note: Generally the tanween (n) is also apply to the proper nouns such a name of a person e.g. Aisha, Fatima etc.  but for English translation "a" or "an" is omitted.  Not all female names ends with tanween - dhamaah   is quite possible.  There are many other exceptions that will learn in advance lessons.