form vs manner

form and manner both are nouns.

Word	Noun	Adjective	Verb	Adverb
form	Yes	No	Yes	No
manner	Yes	No	No	No

As nouns, manner is a hypernym of form; that is, manner is a word with a broader meaning than form:

Other hypernyms of form include fashion, mode, style, way.

As nouns, manner is a hyponym of form; that is, manner is a word with a more specific, narrower meaning than form:

form: a category of things distinguished by some common characteristic or quality
manner: a kind

form (noun)	manner (noun)
the spatial arrangement of something as distinct from its substance	a way of acting or behaving
a life-size dummy used to display clothes	how something is done or how it happens
a mold for setting concrete	a kind
the visual appearance of something or someone
any spatial attributes (especially as defined by outline)
an ability to perform well
a particular mode in which something is manifested
alternative names for the body of a human being
a perceptual structure
a category of things distinguished by some common characteristic or quality
the phonological or orthographic sound or appearance of a word that can be used to describe or identify something
a printed document with spaces in which to write
an arrangement of the elements in a composition or discourse
a body of students who are taught together
(biology) a group of organisms within a species that differ in trivial ways from similar groups
(physical chemistry) a distinct state of matter in a system; matter that is identical in chemical composition and physical state and separated from other material by the phase boundary

form (verb)	manner (verb)
give shape or form to
assume a form or shape
make something, usually for a specific function
create (as an entity)
establish or impress firmly in the mind
to compose or represent
develop into a distinctive entity