The active perfect is a fourteen-position paradigm. Observe where final wāw becomes alif and where it reappears with an attached ending.
PronounActive perfect
هودَعَا
هما (مذکر)دَعَوَا
همدَعَوْا
هيدَعَتْ
هما (مؤنث)دَعَتَا
هندَعَوْنَ
أنتَدَعَوْتَ
أنتما (مذکر)دَعَوْتُمَا
أنتمدَعَوْتُمْ
أنتِدَعَوْتِ
أنتما (مؤنث)دَعَوْتُمَا
أنتندَعَوْتُنَّ
أنادَعَوْتُ
نحندَعَوْنَا
Key contrast: دَعَا، دَعَوَا، دَعَوْا are not interchangeable; each identifies a different person/number combination. دَعَوْتُ reveals the root consonant with the first-person ending.