Personal letters follow looser rules than formal ones — but they still have a shape. Learn how to write to friends and family in a way that actually sounds like you.
An informal letter is a conversation on paper. The structure exists to give the letter shape — not to make it sound stiff.
Informal letters are written to people you know personally: friends, family, or close acquaintances. Unlike formal letters, they welcome contractions, personal opinions, humour, and a warm, conversational tone. The structure is far more relaxed, but a few conventions still make the letter easier to read.
This guide covers the loose structure of an informal letter, how to open and close warmly, and how tone changes depending on who you're writing to — before testing your understanding with ten practice questions.
Informal letters open with a first-name greeting, often followed by an exclamation mark rather than a comma, to set a warm tone immediately.
Dear Priya,
Hey Sam!
Hi Grandma,
Unlike a formal letter, an informal letter doesn't need to state its purpose immediately. It's common to open with a friendly line — asking how the person is, referencing something recent — before getting to the main news.
I hope you're doing well! It's been way too long since we last caught up, so I thought I'd finally sit down and write.
The body can wander between topics the way a real conversation would — news, questions, small stories, opinions. Contractions ("I'm," "we've," "can't") are completely natural here, and so is humour, as long as it fits your relationship with the reader.
| Formal Letter | Informal Letter |
|---|---|
| I am writing to inform you... | Just wanted to let you know... |
| I would be grateful if... | Could you maybe...? |
| Please do not hesitate to contact me. | Let me know if you need anything! |
The sign-off should reflect how close you are to the reader. "Love," and "Take care," suit family and close friends; "Best," or "Talk soon," suit slightly more casual acquaintances.
Write back soon — I want to hear all about the trip!
Love,
Maya
"Informal" isn't a single fixed tone — a letter to a grandparent, a childhood friend, and a new pen pal will all sound different, even though none of them follow the strict rules of a formal letter.
A letter to a grandparent might avoid slang and keep sentences a little more complete out of respect, while a letter to a best friend might use fragments, inside jokes, and abbreviations freely. Both are informal — the difference is calibration, not a rulebook.
Here is a complete informal letter that shows the warm-up, the conversational body, and a closing matched to the relationship — all in one piece.
Dear Grandma,
I hope you're doing well! It's been way too long since we last caught up, so I thought I'd finally sit down and write.
School's been busy — I just finished my science fair project on volcanoes, and it actually won second place! I've also been practising cricket every weekend with Dad, and I'm getting a lot better at bowling.
We're planning to visit you next month during the holidays. I can't wait to see you and Grandpa, and I promise I'll help you in the garden this time!
Write back soon — I want to hear all your news too.
Love,
Aisha
Notice the informal touches throughout: the exclamation-mark greeting, the warm opening before any news, contractions used freely, and a sign-off ("Love,") that matches how close the writer is to the reader.
Knowing when to relax the rules of Formal Letter Writing (Topic I) — and by how much — is its own skill. Informal letters teach the flexible side of written communication that formal structure alone doesn't cover, and this flexibility becomes useful again later in the series when writing emails.
10 questions. Select an answer for each, then submit to see your score instantly.