_beneficium alicui dare, tribuere_—to do any one a service or kindness.
_beneficio aliquem afficere, ornare_—to do any one a service or
kindness.
_beneficia in aliquem conferre_—to heap benefits upon...
_beneficiis aliquem obstringere, obligare, devincire_—to lay any one
under an obligation by kind treatment.
_beneficium remunerari_ or _reddere (cumulate)_—to (richly) recompense
a kindness or service.
_gratus_ (opp. _ingratus_) _animus_[1]—gratitude.
_gratiam alicui debere_—to owe gratitude to; to be under an obligation
to a person.
_gratiam alicui habere_—to feel gratitude (in one's heart).
_gratiam alicui referre (meritam, debitam) pro aliqua re_—to show
gratitude (in one's acts).
_gratias alicui agere pro aliqua re_—to thank a person (in words).
_grates agere (dis immortalibus)_—to give thanks to heaven.
_gratiam mereri_—to merit thanks; to do a thankworthy action.
_par pari referre_—to return like for like.
_paria paribus respondere_—to return like for like.
_bonam (praeclaram) gratiam referre_—to reward amply; to give manifold
recompense for.
_benefacta maleficiis pensare_—to return evil for good.
_maleficia benefactis remunerari_—to return good for evil.
_pro maleficiis beneficia reddere_—to return good for evil.
[1] _animus_ is used similarly in several periphrases to express
abstract qualities—e.g. _animus inexorabilis_ = inflexibility,
severity; _animus implacabilis_ = implacability; _animus (fides)
venalis_ = venality. Cf. _simplices mores, simplex natura, ratio,
genus_ = simplicity (_simplicitas_ is post-Augustan and usually =
frankness, candour). _immemor ingenium_ = forgetfulness (_oblivio_ in
this sense is not classical).