passers-by
The plural form for the compound noun passer-by is passers-by.
The noun 'passerby' is the singular form. The plural form is passersby.
The singular form is passerby; the plural for is passersby.
passersby
passers-by
The possessive form for the noun passerby is passerby's.
The possessive form of the singular noun passerby is passerby's.example: That's a passerby's dog barking.
Passerby
There is no plural form. Do and Do not are verbs
The plural form of him, her, or it is them. (objective pronouns)
Bridges is the plural form of bridge.
"Passerby" can be spelled alternatively as "passer-by," so, conceivably, you would want to say "passers'-by," though you may just want to find another noun to convey the same meaning without the confusion.