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.