you would use masculine and feminine articles when talking about a word that has a gender assigned to it. You use the articles to match the gender that the word has. For example if a word was feminine you would know not to use a masculine article and instead a feminine article. You also use these articles when talking to a person of a specific gender. you correlate the article with the gender that he person you are speaking to is. For example you would not use a adjective that is masculine to a female, instead you would change it to the feminine version because the peeps you’re talking to is a female. Hope this helped :)
You are use feminine articles when using vocab that typically ends in an essay, there are a few exceptions. When using masculine, you use it when the word ends in a consonant or any other with a letter other than A. When you are using articles certain words have certain gender related articles assigned to them.