Going upstairs I think I have a sad face? (8)
I believe the answer is:
emoticon
'think i have a sad face?' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'going upstairs i' is the wordplay.
I cannot really see how this works, but
'going' could be 'on' (both can mean functioning or activated) and 'on' is present in the answer.
'i' is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for emoticon that I've seen before include "Representation of a facial expression in electronic messages" , "Textual symbol" , "Representation of facial expression in e-messages" , "Wordless expression" , "smiley, perhaps?" .)