1. Lagging behind (correct)
Lacking behind (wrong)
2. Expatiate (correct)
Expantiate (wrong)
3. Mincing words (correct)
Mixing words (wrong)
4. Tuck-in (correct)
Tore-in (wrong)
5. Steer clear from me (correct)
Stay clear from me (wrong)
6. Brisket bone (correct)
Biscuit bone (wrong)
7. Rack your brain (correct)
Crack your brain (wrong)
8. Enmity (correct)
Enemity (wrong)
9. Put to birth (correct)
Put to bed (wrong)
10. Pent house (correct)
Paint house (wrong)
11. Fork (correct)
Ferk (wrong)
12. “The end” or “extreme” (correct)
Extreme end (wrong)
13. Postpone (correct)
Pospone (wrong)
14. Adding insult to injury (correct)
Adding salt to injury (wrong)
15. As and when due (correct)
As at when due (wrong)