Verb -ing or to

Eating food on a subway or bus is bad manners.

It's rude to cut in line.

You should try to keep your voice down in public.

You can offend someone by not bowing or shaking hands when you meet.

People might stare at you for walking around barefoot.

Having an argument in public is considered bad manners.

It's impolite to walk into someone's home without taking off your shoes.

Verb+ING as a subject

Preposition + verb+ING

It's ... + to +verb

Gerund as a subject: Eating in public is bad manners.

Not shaking hands is impolite.

Gerund after prepositions: You can offend people by chatting in public.

People might stare at you for not shaking hands.

Infinitive after It's: It's impolite not to shake hands.

It's bad manners to eat in public.