In InE, the word formality (yes, we use it in singular!) is too often used in different contexts. And in most of the cases (especially in a social matter), the word, contrary to its definition, means something with no serious intention/willingness!
An example is here:
Tarun never wanted her to attend his wedding. Though, for the sake of formality, he asked.
And how would Tarun ask (the tone is different as it's for the sake of formality)...
Hey Tia, I'm getting married on Friday. But I think you must be busy on that day. It's okay if you can't make it. :)
Now the definitions of 'formalities':
- a requirement of rule, custom, etiquette, etc
- the condition or quality of being formal or conventional
- strict or excessive observance of form, ceremony, etc
- an established, proper, or conventional method, act, or procedure
No definition makes formalities a light word, an optional material!
OALD describes a thing that you must do as a formal or official part of a legal process, a social situation, etc -Again, it does not, by any account, makes the word light or optional.
Now, in my case, it was not a 'must-do' thing for Tarun to ask Tia. In fact, in India, putting the word for the sake of formality removes the condition of must-do. That's because Tarun certainly takes inviting Tia as an option and it's not at all mandatory.
The question: May I use formality as a singular word? *May I use formality/ies the way I used in Tarun's case when things are not mandatory? If I'm heading somewhere else, how serious natives take while speaking of formalities?