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

little talk • small talk
little talk —
1
. a brief comment or address: Let me illustrate
by a little talk, which I think will have the twang of realism
about it. 2. a short conversation: “Mr. Baker and I had a little
talk about you today,” Newton said.
small talk —light social conversation about unimportant
things: After Willoughby was gone, Karen tried to make small
talk.
Note: 
Neither expression is antonymous in meaning to the
phrase big talk—(also: tall talk) boastful or pretentious talk: We
don’t want big talk from an armchair critic.
little thing • small thing
little thing —
1
. a small child: There are the shops where she
used to buy me toys when I was a little thing. 2. is used as a
term of endearment: Poor little thing! He misses his mammy,
you know! 3. smth. unimportant; a mere trifle: I never saw
such an excitement over a little thing in Arkansas as there was
over that debate.
small thing — = little thing 3: The First World War was fought
over a small thing. A scrap of paper. Cf.: big thing — smth. of
considerable importance: The big thing for guys is jeans or
slacks, button-down shirts and brown loafers without socks.
Note: 
The expression does not correlate in meaning with the
phrase do that small thing—(coll.) do smth. indicated in a pre-
vious statement: “I’m going to have a bath.” “Darling, you do
that small thing!”
little world • small world
little world —
1
. the limited close circle of one’s family and
friends: I see a chap who is a sort of great white chief in his
own little world. 2. a group of things considered as constitut-
ing a unity: The archipelago is a little world within itself, or
rather a satellite attached to America.
small world —(also: it’s a small world) used as a comment on
an unexpected meeting with a person: “Small world,” he said.
“That bloke was in here yesterday.”
See also: great world, the / greater world, the.