I have found some alternatives to gratias tibi ago in the literature. I limited my search for simple, conversational thank yous. These fall into two broad groups:
- Thanks expressed using “thanksgiving”:
habeo gratiam
This occurs frequently in Plautus, often standing alone for a straightforward “thank you”. It also appears in Terence’s The Brothers.
fateor, habeo gratiam
I admit it, thank you
Plautus, Persa
Here it is with the object of thanks in the dative:
Epidico habeas gratiam
you should thank Epidicus
Plautus, Epidicus, act 2, scene 2
gratum/grata mihi est
Cicero uses this quite a bit. A couple of examples:
domum meam quod crebro invisis est mihi valde gratum
thank you very much for keeping a close eye on my house
Letters to Atticus, 80 (IV.5), Antium, soon after 79
… tamen mihi grata hortatio tua est
nevertheless, thank you for your encouragement
De Finibus, 5.6
Here without the dative pronoun:
gratum est quod patriae civem populoque dedisti
thank you for producing a citizen for the fatherland and the people
Juvenal, Satires, 14.70
Here alone:
gratum est
thank you
Seneca, Medea, act 3, line 553
Even more brief:
quod Lucceio scribis te nostram gloriam commendaturum et aedificium
nostrum quod crebro invisis, gratum
for writing that you will recommend my glory to Lucceius and for
keeping a close eye on my home, thanks
Cicero, Letters to Atticus, 85 (IV.9), Naples, 27 April 55
- Thanks expressed as pleasure and assent to the preceding
action/suggestion etc:
bene facis
Iuppiter: iam nunc irata non es? / you’re not still angry, are you?
Alcumena: non sum / no, I’m not
Iuppiter: bene facis / thank you
Plautus, Amphitryon, act 3, scene 2
bene vocas
Here, combined with gratia est:
Erotium: eamus intro, ut prandeamus / let’s go inside and have lunch
Sosia: bene uocas, tam gratia est / thanks but no thanks
Plautus, Menaechmi, 2.3.36
bene
“en” inquit, “hospitium”. “Bene” ego …
“Welcome” he said. “Thanks” I replied …
Apuleius, Metamorphoses, 1.22
optime
“nam et a te perfici istam disputationem volo nec tua mihi oratio
longa videri potest.” “Optime,” inquam …
“for I wish that you finish your argument and no speech of yours could
seem to me long.” “Thank you very much” I said …
Cicero, De Finibus, 4.44