The root د خ ل means entering. Keep its action and add the same past-tense endings:
● دَخَلَ — he entered
● دَخَلَتْ — she entered
● دَخَلْتُمْ — you men entered
● دَخَلْتُنَّ — you women entered
● دَخَلْنَا — we entered
The root changes from ك ت ب to د خ ل, but the pronoun endings keep the same jobs.