1. Three words meaning Pretend, Condescend, and the Period under a king or queen differ by a sing letter. What are the words?

2. Three words meanings: Sew, Swap, and Inform on someone - differ by a single letter. What are the words?

3. Three words meaning Direct, Costume, and Duplicity - differ by a single letter. What are the words?

4. Three words meaning A cry,  A chicken, and A hood differ by a single letter. What are the words? 

5. Three words meaning Apartment, Achievement, and Edict - differ by a single letter. What are the words? 

6. Two words differ by a single letter. One you sit on and one you sing in. What are the words? 

Answers:

1. FEIGN, DEIGN, REIGN

2. STITCH, SWITCH, SNITCH  

3. GUIDE, GUISE, GUILE 

4. HOWL, FOWL, COWL 

5. FLAT, FEAT, FIAT 

6. CHAIR and CHOIR