Nouns: gender

1) General rule
English nouns rarely change form, even to indicate gender. As a general rule, only nouns referring to people and some animals reflect gender in their form. By the same token, unlike many other languages, the adjectives modifying nouns will remain unchanged.

Example: My poor little dog died.

2) However, certain nouns -- especially those referring to people -- may have different forms to indicate masculin or feminine usage:

man -- woman
gentleman -- lady
actor -- actress
uncle -- aunt
father -- mother

The same can be said of certain male and female animals:

a buck, a doe
a ram, a ewe
a bull, a cow
a stallion, a mare

3) In other cases, the word "male" or "female" is added, if it is considered necessary to be specific:

a female cat
a male giraffe

4) Pronouns
Note: If the gender of the person or animal is known, one will generally use the pronoun "he" or "she" to refer to it, as appropriate. When the gender is left unstated, the pronoun "he" is generally used when speaking of people, or "it" when speaking of animals. Some objects are also considered to be gendered in certain usages: some people may refer to a boat or a car as "she."

5) Man/Woman
Certain nouns (especially the names of professions) are traditionally associated with men or women, in which case one signals exceptions to the tradition by adding "woman" (or "lady") or "man" to the term:

They are in a group of male dancers.
My wife prefers to see a woman doctor.