If a masculine noun ends in -о, making it feminine will change the ending into –а:
chico (boy) – chica (girl)
gato (tom-cat)
– gata (female cat)
If a masculine word ends in a consonant, the female noun will be formed adding –а:
profesor (male teacher) – profesora (female teacher)
If a masculine noun was stressed on the last syllable, in its feminine form the stress disappears:
león (lion) – leona (lioness)
francés (Frenchman)
– francesa (Frenchwoman)
If a masculine noun ends in –е and means a profession, its feminine is formed by changing the ending into –а:
el jefe (male boss) – la jefa (female boss)
el presidente (male president) – la presidenta (female president)
The rest of the words in their feminine version remain unchanged and their gender will only be indicated by the determinative:
el paciente (male patient) – la paciente (female patient)
We should particularly mention the words with the suffix –ista, which also have the identical form for both genders:
el pianista (male pianist) – la pianista (female pianist)
A single form for both genders is also typical of words that end in –a
belga (Belgian man/woman), croata (Croatian man/woman), maya (Maya Indian man/woman), azteca (Aztec man/woman), inca (Inca man/woman), …