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

in form • on form
in form —
1
. in structure: Cretan buildings are simple in
form, conforming to architectural norms of Byzantine prove-
nance. 2. in good physical or mental condition: Even if a horse
is in form a bad trip almost surely will cancel its chances. 3.
as a mere formality: The laws, which heretofore existed only
in form, have been thoroughly enforced.
on form —
1
. on the basis of previous results: On form, they
have no chance of winning today. 2. = in form 2: We all knew
that Michael was always on form when he played and he
exceeded his own expectations today!
in front of something • in the front of something
in front of something —in the position directly before smth.:
She couldn’t watch the television because he was standing in
front of the screen.
in the front of something —in the foremost or most important
part of smth.: Two rooms were built in the front of the west
end of the house.
Note: 
The expression is not equivalent in meaning to the phrase
at the front of something
—
1
. in the position nearest to the front
part of smth.: At the front of the machine is the feeding board,
a large wooden surface sloping gently down. 2. involved in the
most advanced developments in a particular field: The Beach
Boys are at the front of this wave of frantic surf music.
in full • to the full
in full —(of payments, etc.) without leaving anything out;
to the full amount: It was part payment only, payment in full
was still to come.
to the full —as completely as possible; to the greatest degree:
We did not enjoy our holiday to the full, because we were
worried about my father.
in full spate • in spate
in full spate —
1
. (of a current of water) at abnormally high
level: This stream cannot be crossed when it is in full spate.
2. said of some intense activity: A migration into the valley
continued in full spate beyond the middle of the century. 3.
said of an outpouring of unrestrained speech: He was in full
spate…. What he was talking about was that they would send
off one of these surface-to-air missiles.
in spate — = in full spate 
1
: The worm fisher has his oppor-
tunity when the streams are in spate.