这些词后加doing还是to do

help sb (to) do
keep doing
feel doing/feel like to do
thing about doing

除了help to do 都是doing

help 一般加动词原形do
keep doing
feel like doing
think about和doing或者to do不是词组

hope 加不带to的动词不定式。
keep doing
feel doing
think about doing

help to do…

keep doing…

feel doing…

think about doing…