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

have a say • have the say
have a say —
1
. (also: have a voice) have the right or the oppor-
tunity to give one’s opinion: People want to have a say in how
the country should be governed. 2. give one’s opinion on a
matter: The 75-year-old Rossi announced he would be leaving
… and he has had a say in who his successor will be.
have the say —have the power of deciding; have the final
authority: We keep giving recommendations but at the end
of the day — who has the say? It’s the government.
have a screw loose • there is a screw loose
have a screw loose —(coll.) be mentally defective or not acting
normally: I don’t go much with anarchists. It’s my judgment
they nearly always have a screw loose.
there is a screw loose —(coll.) there is smth. wrong in the con-
dition of things: Now this may come into court, you know.
If there is a screw loose anywhere, better mention it.
Note: 
Neither expression is antonymous in meaning to the
phrase tighten up screws—
1
. suppress or “clamp down” on dis-
senters, etc.: The president is using Russo-American rapproche-
ment as a smokescreen for tightening up screws at home.
2. apply pressure; make smth. subject to more severe control:
Dellinger believed the victory was a result of his team tight-
ening up screws on defense.
have a swelled head • have a thick head
have a swelled head —(also: have a big head) have an exag-
gerated opinion of oneself; be self-conceited: Everybody over
forty is tired and down and out, and everybody under thirty
has swelled head.
have a thick head —(coll.) 
1
. be dull of intellect: You could
have worked that out for yourselves if you hadn’t such thick
heads. 2. have an aching head (suffering from a hangover):
No more brandy, thanks. I’ll have a thick enough head as it
is.