/ ˈpɑːtli; NAmE ˈpɑːrt-/ adverb
to some extent; not completely :
Some people are unwilling to attend the classes partly because of the cost involved.
He was only partly responsible for the accident.
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WHICH WORD
partly / partially
Partly and partially both mean 'not completely':
The road is partly / partially finished.
Partly is especially used to talk about the reason for something, often followed by because or due to :
I didn't enjoy the trip very much, partly because of the weather.
Partially should be used when you are talking about physical conditions:
His mother is partially blind.