My son uses fuck or fucking to emphasize his statements. I told him there are words that you can use that aren't so offensive for my 3 year old grandchild to parrot! He asked what word is so globally understood to add emphasis. Also, I am looking for a list of words.
May I be so bold to suggest that it's not emphasis but restraint that is called for here? Raising children myself I know how easy it is to transfer bad habits without meaning to.
Children should be enabled to acquire these bad habits later-on as an adult or at least after puberty sets in.
Definition of restraint in English:
Unemotional, dispassionate, or moderate behaviour; self-control:
'he urged the protesters to exercise restraint'
It's unclear what the exact circumstances are, but when every third word someone utters is "fuck" or "fucking" it's not for "emphasis". In fact the the ability of the word to "emphasize" is lost when used with such frequency. What they're demonstrating is an inability/unwillingness to think clearly about what they intend to say.
"Fucking" as an adjective or adverb can often be replaced by "very". Eg. "It is fucking hot" means "it is very hot". Therefore you can replace "fucking" with more elaborate adjectives such as "extremely", "amazingly" or "incredibly".
"Fuck" can also be used as an arbitrary exclamation, and can be replaced by something colloquial like "wow" or "crikey". Eg. "Fuck, it's hot" means "Wow, it's hot".