grosse = fat
grande = big
grosse = fat, big
grande = tall
shouldn't "the woman is tall" also be correct?
no. Grande would be accepted for tall. Grosse is big.
How do I know when La femme = the wife or the girl? Was this covered?
I asked this question somewhere else. The answer I got was that if there's a possesive form (ie: MA femme) it's wife, if not (ie: LA femme) it's woman. Made a certain kind of sense too! :)
La femme is the woman and the girl is la fille.
Why not "Gros" instead of "Grosse" ?? We used it in "Le chien est gros"
"Gros" is masculine. If you were talking specifically about a bitch, you'd have to say, "Le chienne est grosse."
... And that makes me curious: does "chienne" have the same slang meaning in French as "bitch" in English?
Yes, chienne is used in very much the same way as bitch. You may also be interested to know that chatte is used in a similar, non-feline, sense.
I knew that "grosse" in french can also mean "pregnant", am I wrong?
Only for cows or other mammals. Not women who are "enceintes".