F TO O

fallible

infallible

fidelity

infidelity

finite

infinite

flexible

inflexible

formal

informal

frequent

infrequent

gratitude

ingratitude

hospitable

inhospitable

human

inhuman

humane

inhumane

justice

injustice

offensive

inoffensive

opportune

inopportune

S TO V

sane

insane

satiable

insatiable

sensitive

insensitive

sensitivity

insensitivity

separable

inseparable

separably

inseparably

significant

insignificant

sincere

insincere

sincerely

insincerely

solvent

insolvent

stability

instability

substantial

insubstantial

sufficient

insufficient

susceptible

insusceptible

tangible

intangible

valid

invalid

variably

invariably

vulnerable

invulnerable