A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

hold something on • keep something on
hold something on —secure smth.; keep smth. in position:
This big screw holds the lid of the box on.
keep something on —
1
. continue to possess smth.: We are still
keeping on the house in France. 2. continue to wear or use
smth.: In a church men take their hats off; in a synagogue,
they keep them on. 3. = hold something on: There is a spring
underneath so use a finger to keep the lid on while you remove
the last screw.
hold something out on someone • hold something
out to someone
hold something out on someone —keep a secret or news from
a person: What’s going on? Are you holding something out
on me?
hold something out to someone —offer smth. to a person: I
held out an offer of immunity to prosecution to her, but she
would not cooperate.
hold something up • keep something up
hold something up —
1
. support smth. physically; bear the
weight of smth.: We couldn’t hold up the fence, and it finally
fell over. 2. (of prices, etc.) cause to remain high: Efforts were
made to hold up the price by again cutting production. 3.
stop or delay smth.; make smth. late: A heavy storm in Boston
held up our plane. 4. stop a car, etc. in order to rob: The
thieves held up a van carrying a factory payroll.
Note: 
a) The expression does not correlate in meaning with
the phrase uphold something—
1
. (of a law, etc.) support and
maintain smth.: We will loyally uphold the principles of the
United Nations. 2. (of a verdict, decision, etc.) confirm or
endorse: His court conviction was upheld on appeal.
b) The expression does not correlate in meaning with the phrase
hold up on something
— delay doing smth.: I have to hold up
on my reading because I broke my glasses.
keep something up —
1
. = hold something up 
1
: My husband
lost so much weight that he has to wear a belt to keep his
trousers up. 2. = hold something up 2: Since it is “back-to-
school” time, I expect lots of students are buying laptops, and
are keeping the prices up. 3. keep smth. in good condition;
maintain smth.: How do you keep up a house as large as this
without help? 4. continue smth.: Jane will have to keep up
her piano practice if she wants to be a professional performer.