Pimsleur courses teaches languages to a conversational level. No grammar, no reading/writing. Just listen and repeat. Another great way to build up your functional vocabulary is once you've completed level 1, start translating articles and blog posts in topics you're interested in. You'll be surprised how fast you'll start to progress. Each lesson is 20-30 minutes. I surpassed my wife in functional German after a few weeks and she had been religiously working at Duolingo for nearly a year, she knows words but can't use them. Pimsleur can be found for free download online if you look in the right places.