effortlessly
The service in the restaurant was effortfully attentive.
He stood up effortfully and shook the crumbs off his jumper.
His grandmother uses her second language unnaturally and effortfully.
She sang in an effortfully pure soprano voice.
He hobbles round the stage effortfully.

SMART Vocabulary: related words and phrases

Effort and expending energy
assiduity
assiduous
assiduously
assiduousness
be running on emptyidiom
burn
effort
effortful
elbow grease
fight
hamster wheel
hard at itidiom
kill
plough
plough through something
push
put something in/put something into something
rearguard action
set/put your mind to somethingidiom
swing