Yes.
"Threatening to kill, he quickly advanced forward."
I took an umbrella with me as the angry clouds were threatening rain.
i threatened her to get into the van.
The threatening dog stood in the path, baring its teeth.
can you start a sentence using the word phishing?
"Mum always curtails my moaning by threatening to ground me."
no!
What is cystic fibrosis? Cystic fibrosis is a life threatening disease.
This animal is a threatened species or they threatened my life.
No, you cannot start a sentence with "no" unless you need to do so. No reason exists not to start a sentence with that word, as you can see. No one will care if you do start a sentence with it.
What sentence would you like?
When it is at the start of a sentence.
start it out with the