Regular German tutoring for secondary school student in Basel

Hello, I am looking for regular German tutoring for our 2 sons. One is in secondary school level (2nd sec) and the other is in his final year of primary school.. I am looking for tutoring support in Basel. The lessons should be individual. We can meet at our place or do the sessions online. Our general availability is noted in my profile. My goal is to build stronger skills and feel more confident High German Grammer at school. If you think you could support us, I would be happy to hear from you.