ils montaient

were going up, were climbing

→ monter
mont to go up, to climb + aient they were ...ing (imperfect past)
verb · third plural · imperfect indicative Rare #45,551
were going up, were climbing
FR: Ils montaient l'escalier rapidement.
EN: They were going up the stairs quickly.
Conjugation of monter
Indicative imperfect
SingularPlural
Third montait montaient

Et s'ils montaient?

What if they went up?

— La Plateforme (2019)

Ils montaient la garde chaque nuit, ils mettaient des pièges, des filets.

They stood guard every night; they set traps and nets.

— Heureux comme Lazzaro (2018)

Toutes ces grandes phrases qui montaient dans ma gorge.

All those grand phrases rising in my throat.

— Moscou ne croit pas aux larmes (1980)

Les tensions montaient.

Tensions were rising.