I'm glad that Portuguese doesn't try to trip up foreigners on purpose here, like Spanish does with "el agua" (which is still a feminine word, but takes the masculine article because "la agua" is too hard to pronounce).
French does this too: "mon" is masculine, "ma" is feminine, "ami" is masculine (so "mon ami" is correct), "amie" is feminine, but you have to say "mon amie". Some things contract (like "n'est", "c'est", "l'homme"), but not "ma."
I'm glad that Portuguese doesn't try to trip up foreigners on purpose here, like Spanish does with "el agua" (which is still a feminine word, but takes the masculine article because "la agua" is too hard to pronounce).