This root form (lemma) is used in 3 different forms in the NT: ἐστερέωσεν (IAA3··S), ἐστερεοῦντο (IIP3··P), ἐστερεώθησαν (IAP3··P).
It is glossed in 3 different ways: ‘were strengthened’, ‘were_being strengthened’, ‘strengthened’.
OET ACTS 3:7 Greek word=ἐστερεώθησαν (estereōthaʸsan) Morphology=IAP3··P English gloss=‘were strengthened’ SR GNT ACTS 3:7 word 14
OET ACTS 3:16 Greek word=ἐστερέωσεν (estereōsen) Morphology=IAA3··S English gloss=‘strengthened’ SR GNT ACTS 3:16 word 14
OET ACTS 16:5 Greek word=ἐστερεοῦντο (estereounto) Morphology=IIP3··P English gloss=‘were_being strengthened’ SR GNT ACTS 16:5 word 5