1) What should be output when there are no words starting with input string? 2 successive empty lines in the output are weird, so I ask.

2) If input contains some word exactly as it is, should I place this word in the output? I.e. does the verb "start" allow equality as well?

Ok, my AC solution treats equal strings as starting and it will output two blank lines in case of empty result between two non-empty ones.

What about ten empty results between two non-empty ones?