I'm grateful that Henry's on time (6)
I believe the answer is:
thanks
'i'm grateful' is the definition.
I know that 'grateful' relates to this answer.
'henry's on time' is the wordplay.
'henry's' becomes 'hanks' (short for Henry).
'on' means one lot of letters go next to another.
'time' becomes 't' (abbreviation).
'hanks' put after 't' is 'THANKS'.
'that' acts as a link.
Can you help me to learn more?
(Other definitions for thanks that I've seen before include "Word of appreciation" , "Expresses gratitude" , "I am grateful" , "recognition?" , "Polite acknowledgment" .)