No tasks available after few accept or reject in ner.teach

When using ner.teach, keep in mind that you're not just annotating every example. Prodigy will actively look for the most relevant examples to annotate, meaning it will skip some examples in favour of others. See this thread for more details:

Yes, in ner.teach, you're collecting binary feedback on specific annotation suggestions. So you're accepting or rejecting the currently highlighted entity span.