Instructional Tools

I'm not doing online teaching because I don't know how many of them would take part seriously and actively. So I have been using WhatsApp and Email as my instructional tools. Now I'm very busy marking students' essays and sent them back via their emails. However, for language grammar questions, I have sent them via WhatsApp. Now I can assume that how many of them really serious and interested in doing the tasks. During this PKP period, I have been allocating two to three hours daily for this purpose.