common
Strikes are the most common form of industrial protest.

different, various
various forms of surveillance

extreme
an extreme form of socialism

pure
In its purest form, the substance is highly explosive.

basic, simple
complex
mild
severe, virulent
a virulent form of the flu

early, original, traditional
an early form of bicycle

final
The document was edited before being circulated in its final form.

new
art, literary, musical
Storytelling has acquired the status of an art form.

life
primitive life forms at the bottom of the sea

digital, electronic
The data is stored in digital form.

graphic, tabular
The results of the survey are shown below in tabular form.

liquid
physical

take
Bullying can take many forms.

give
A film gives physical form to a novel's characters.

in … form
The gas is stored in liquid form.

in the form of
These costs were passed on in the form of higher rents.

form of
Swimming is one of the best forms of exercise.

in any shape or form
The company will not tolerate discrimination in any shape or form.

in some form or other
We spend most of our time communicating in some form or other.

human
paintings of the human form

adult
sleeping

alter, change
a mythical creature that could change its form

assume, take on
a god who could take on human form

in a/the form
Two weeks later the moth will emerge in its adult form.

application, booking (BrE), consent, entry, order, registration, reservation (AmE)
online
Please fill out the online form on our website.

complete, fill in (BrE), fill out
Please complete the application form and return it to us.

sign
return

fine, good, great, top
The team entered the tournament in top form.

poor
current, present

maintain
The team is hoping that it can maintain its current form.

find
She urgently needs to find her form.

regain

in form
She was in fine form for the tournament.
Ben was in great form at the wedding.
Barcelona are the team in form. (BrE)

off form (BrE)
Her recent illness possibly explains why she was off form in this race.

on form (esp. BrE)
He'll be a difficult opponent to beat; he's really on form today.
Yesterday's game saw him back on form.

on sb's form (esp. BrE)
On his present form it seems likely that he will win.

out of form (BrE)
The team was out of form and did not play as well as expected.

a return to form
His recent performances mark a welcome return to form.

attempt to, try to
agree to, decide to
ask sb to, invite sb to (both esp. BrE)
The leader of the party with the most seats is invited to form a government.

help (to)

newly formed, recently formed
a newly formed political party

into
She formed the clay into a ball.

fully formed
The plan came in a flash of inspiration, fully formed.

perfectly formed
a perfectly formed body

Form is used with these nouns as the subject:
bruise, bubble, cell, clot, cloud, consensus, crust, crystal, dew, grin, group, ice, idea, lump, mould, perspiration, queue, rock, scar, smile, tear, wrinkle

Form is used with these nouns as the object:
administration, alignment, alliance, angle, arc, arch, army, assembly, association, attachment, backdrop, background, band, barricade, barrier, base, basis, blockade, body, bond, border, boundary, brigade, cabinet, canopy, carpet, category, cell, chain, channel, character, circle, class, climax, clot, cloud, club, clump, coalition, coating, colony, committee, commune, company, compound, confederation, congregation, connection, consensus, cooperative, cordon, core, council, crater, crust, curve, deposit, division, edge, element, elite, entity, expectation, federation, fist, focal point, force, foundation, friendship, front, frown, galaxy, government, grin, groove, group, habit, hierarchy, hypothesis, ice, idea, identity, image, impression, infinitive, judgement, junta, layer, league, line, link, lobby, loop, lump, majority, militia, mob, molecule, network, opinion, ozone, pact, part, partnership, party, paste, pattern, perimeter, picture, plan, pool, procession, queue, relationship, republic, ring, rock, sentence, shape, shield, skeleton, society, spine, squad, structure, style, subsidiary, syndicate, task force, team, tense, triangle, trust, union, unit, valley, vapour, web, whole, word