the boy was acting very safe.
Safe can be an adjective. It is also a noun.
The children were found safe and sound inside the house.
The Mesopatamians used the phalax to keep their children safe.
'He reached safe.' is incorrect. The noun 'safe' is a word for a metal strongbox. I don't think that he was reaching for a safe. If he was, then it should say 'a safe' or 'the safe'. The other use of the word 'safe' is an adjective, a person can't reach for an adjective. The noun form for the adjective 'safe' is 'safety'. A correct sentence is 'He reached safety.' (a safe place).'Please speak loud.' is technically correct, the word 'loud' is an adverb but it sounds a bit clumsy. Alternates are 'Please speak loudly.' or 'Please speak aloud.' Both 'loudly' and 'aloud' are also adverbs which can modify the verb 'speak'.
terrorist will not find a safe haven here.
I can give you several sentences.I have home and automobile insurance.His insurance that we would be safe didn't make me feel much better.Your helmet gives insurance against a head injury.
After locking the door, she felt safe in her own home.
if you are more safe you are saferif you are less safe you are dangerous/vulnerable
I always make sure to lock the door to keep my valuables safe when I leave the house.
Safe, sensible driving means increased fuel efficiency
my cat looks safe in her cage
"It's safe to say that Kurt Cobain, with Nirvana, was the progenitor of "grunge" music"