This is my personal experience with learning French.  I studied French for seven years and I think the most productive learning was when I was in seventh grade.

Paris France how to learn French

Why was this the most productive time?  Was it that I was so young and language learning is easy people say when you are young? No. The reason was my French teacher Madame Lessard (truly a great woman), made us memorizes dialogues.  I still remember those dialogues to this day. She made us recite them.  I leaned so many words and phrases that this was much better than doing book work and she made it fun.

Memory French language learning

A language is largely based on memory.  You need to learn words or dialogues.  If you can remember passages from the Bible or common everyday dialogues or word lists you will not have a problem with grammar.

Think of the ancients who memorized entire stories, like the Iliad.  If people in ancient times could memorizes entire books, you can certainly memorizes lyrics to a song in French or part of your favorite book.

Some how you are going to have to know about 5,ooo words to start speaking French at a reasonable level. You need to test and retest yourself.

So how did I learn the French language? Honestly I am not that great in French, but I learned it not in Paris or France, but by memorizing passages and words.

How to learn French

If you are not overly motivated to learn passages or have someone like Madame Lessard to guide you (few teachers were like her), I recommend using French flashcards. Flashcard will get you up to speed faster than any other method I know. I learned Polish a much more difficult language this way.