Good morning, everyone.
I wonder whether the form of "adj + -ing" is a short form of "adj + (in) + -ing".
'in' can be omitted in the following examples:
a. I am happy (in) working here.
b. I am exhausted (in) cleaning up after you.
c. I am busy (in) studying at the moment.
'in' cannot be omitted in the following examples:
d. This pill is effective in stopping cough.
e. I am interested in joining your club.
f. Adam is efficient in packing up the goods.
Is "in" idiomatically left out in "adj + -ing" form? thanks very much
In the sentences without 'in', you can reverse the order and use "makes". The complement, in some way, causes the condition that the adjective describes:
a. I am happy working here. "Working here makes me (causes me to be) happy."
b. I am exhausted cleaning up after you. "Cleaning up after you makes me exhausted."
c. I am busy studying at the moment. "Studying at the moment makes me busy."
You can't do this with d - f.
d. This pill is effective in stopping cough. * Stopping the cough makes the pill effective. NO.