Gender asymmetry is an aspect of the constructed international auxiliary language Esperanto which has been challenged by numerous proposals seeking to regularize both grammatical and lexical gender.
Nevertheless, gender is sometimes an issue. In practical usage words formed with the suffix - ul "person" are ambiguous, sometimes used with a masculine meaning in the singular, but generally neutral in the plural. However, concepts of gender have changed over time, and many words that were once considered masculine are now neutral, especially words related to professions and animals.
In older texts it is only context that disambiguates. In modern usage, most noun roots are lexically neutral, a couple of dozen are lexically masculine, and a smaller number lexically feminine.
Most masculine roots may be made feminine through the addition of the suffix - ino and made to describe a group of both males and females with the addition of ge -. For these gendered words there is no easy way to make the singular neutral equivalent. Some neutral counterparts can be made with word-building. The approximate meaning of "parent" can be achieved with gener-into " genitor " or ge-patr-ano "one of the parents".
Gender-neutral roots such as leono "lion" and kelnero "waiter" may be made feminine with a grammatical suffix leonino "lioness", kelnerino "waitress" , but there is no comparable way to derive the masculine; there was not even originally a word for "male". Originally this took the form of a suffix - viro , [ 7 ] [ 8 ] but in response to criticisms that the resulting words such as bovoviro "bull" were ambiguous with mythological man—animal hybrids such as minotaurs also bovoviro , Zamenhof switched to using vir as a prefix in his translation of Genesis finished in Critics such as Dale Spender and Veronica Zundel feel that deriving feminine from masculine words causes women to be either "linguistically excluded… or else named negatively", while others are bothered by the lack of symmetry.
