Counter-intuitively, informal is the register where over-correct English costs marks. A letter to a
close friend that reads "I am writing to inform you that I have recently changed my employment"
is grammatically perfect and stylistically wrong — it doesn't sound like a real letter to a friend, and
that mismatch caps Task Achievement no matter how accurate the grammar is. The fix is deliberately
building a bank of natural, idiomatic alternatives to the "safe" formal-sounding words students default
to under pressure.
0:15 – 0:45
Idiomatic synonym swaps
These are the words students reach for automatically, and the natural, native-sounding alternatives an
examiner expects in a letter to a friend.
Textbook-safe
Natural informal alternatives
Example
nice / good
great, lovely, amazing, brilliant
The food there is absolutely amazing.
sad / disappointed
gutted, down about it, bummed out
I was so gutted when the trip got cancelled.
happy / pleased
thrilled, over the moon, buzzing
I'm over the moon about the new job!
tired
shattered, worn out, exhausted
I've been absolutely shattered all week.
busy
snowed under, run off my feet, slammed
Work's been mad — I've been run off my feet.
surprised
gobsmacked, couldn't believe it, taken aback
Honestly, I couldn't believe it when I heard.
a lot of
loads of, tons of, so much
We've got loads of catching up to do.
very (+ adjective)
so, really, dead (British informal)
It was so weird seeing him again.
Match the intensifier to the emotion, not just the register
"So gutted" and "a bit gutted" are not interchangeable — pick the intensifier that fits how big the
news actually is. Overusing "so" and "really" on everything is its own kind of repetition, and the
examiner notices that too.
0:45 – 1:00
The phrasal-verb mirror
Every phrasal verb you should avoid in a formal letter is exactly the kind of natural language an
informal letter needs. Use this table both directions: check formal drafts for accidental phrasal verbs,
and check informal drafts for accidental single-word formal substitutes.
Formal (avoid in formal letters ✓ used correctly here)
Informal phrasal verb (use in informal letters)
tolerate
put up with
resolve / rectify
sort out
postpone
put off
investigate
look into
cancel
call off
encounter (difficulty)
run into
consider
think over / mull over
recover from
get over
reduce
cut down on
visit
drop by / pop round
Register-check drill
Each sentence is in the wrong register for its letter. Rewrite it using the correct column above.
(Formal letter, but too casual) I'll sort it out by Friday.
(Informal letter, but too stiff) I have decided to postpone the visit.
(Informal letter, but too stiff) I am still recovering from the shock!
1:00 – 1:30
Independent practice — then revise
Use at least four idiomatic swaps and one phrasal verb from the tables above. Submit, identify your
lowest criterion, make two edits, resubmit.
Task 1 — informal letter
You have recently moved to a new city for work. Write a letter to a friend.
In your letter:
tell them about the move and how you're settling in
describe what the new city is like
invite them to come and visit
Begin your letter Dear (name). Write at least 150 words.
Your informal letter
Target: 150+ words · 20 min
Words: 0Not saved yet
20:00
Informal — 20 min
Wrap-up
You've now built a synonym bank across all three registers. Session 5 consolidates everything into one
reference chart, runs a surprise full mock, and finishes with a complete guide to reading all four
AI-marked criteria — so you leave the workshop able to mark your own weak points without help.