Enrolling in advanced language courses is a crucial step in developing higher-level speaking and writing skills, supplementing the basic and intermediate training provided by platforms like Beelingua. These courses often focus on comprehensive language use, including advanced grammar, extensive vocabulary, and complex writing and speaking exercises. 

Advanced courses typically involve a range of activities like giving presentations, engaging in debates, and writing research papers or essays. These tasks simulate real-world language use scenarios, providing learners with the opportunity to practice the language in diverse and challenging contexts. For instance, preparing and delivering a presentation in the target language can significantly enhance public speaking skills, confidence, and fluency. 

Moreover, advanced courses often provide personalized feedback from experienced instructors, which is critical for fine-tuning language skills. This feedback can cover nuances in pronunciation, writing style, and grammar usage, offering insights that are difficult to gain from self-study or generic language learning platforms. 

Taking these courses also provides an opportunity to interact with fellow learners, facilitating collaborative learning and peer feedback. Such interactions are beneficial for understanding different perspectives and gaining insights into the cultural aspects of the language. Advanced language courses fill the gaps left by self-learning platforms like Beelingua, particularly in the areas of advanced grammar, sophisticated writing, and nuanced speaking skills. They offer a structured and comprehensive approach to mastering a foreign language at a higher level.