For guests from across the Atlantic: London companionship, translated

Guests from the United States arrive speaking the language and discover, within a day, that the grammar is different. None of it is difficult. A handful of small translations, made in advance, spare an evening its only awkward minute.

What follows is written from the desk. Octavia hears the same few questions from American guests every season, and nearly all of them have short answers.

Write the month as a word. To a London reader, 4/7 is the fourth of July; to a New Yorker it is the seventh of April. A message that says 7 April leaves no room for argument, and a booking made for the wrong week is the one mistake nobody enjoys untangling.

Floors count differently too. The ground floor is at street level and the first floor is one flight up, what you would call the second. Room numbers follow the hotel's own system, so they are safe, but a companion told to come up to the second floor will go one higher than you intended. The elevator is the lift, the check is the bill, and the restroom is the cloakroom in a restaurant or simply the ladies' and the gents'.

This is where the American instinct needs the most adjustment. In London restaurants a discretionary service charge is often printed on the bill already; read it before adding anything, because paying it twice is a common and silent mistake. Bar staff are not rewarded drink by drink as at home. A porter or doorman who has genuinely helped appreciates a few pounds, and a taxi driver is content if you round up.

For your companion, nothing on top is expected. The figure Octavia confirms is complete. You give it to her yourself as the evening begins, and no gratuity follows at the end. A present is never required either. If you would like to bring one, the Notebook's quiet view is that a book chosen for her beats anything expensive.

London dines at around eight and eats less late than New York does. Kitchens close earlier than an American visitor tends to expect, so a table at half past ten should be confirmed, not assumed. Many pubs still call last orders not long before eleven. Hotel bars keep going later, and a few rooms in the quarter are still pouring well after midnight.

The Tube runs through the night on some lines on Fridays and Saturdays, but after dinner a car is simpler. On foot, look right before you cross. The traffic arrives from the side your instincts ignore, which is why the kerbs in central London say so in white paint.

American guests sometimes expect to make a phone call. The desk works in writing only: WhatsApp or Telegram, at any hour, answered by Octavia herself, with no call line and no text line. Send the date, the time, the length you have in mind and your hotel, and she replies with a companion's name, the minute of arrival and the fee.

Fees are in pounds, whole pounds, from £600 for an hour to £1,800 for the four hour dinner, and they are never restated in dollars. Before your companion sets out, Octavia makes a single check, once and inside the chat: the name on the room's booking, and the room number. An evening here is time and companionship only, and it keeps to exactly that.

Parts of London are easier for an American guest than they look. The American Bar at The Stafford, tucked into a mews behind St James's Place, has been collecting caps, ties and pennants from transatlantic visitors for decades, and a first drink beneath them feels like a handshake. Claridge's and The Connaught, a short walk north into Mayfair, have been receiving American travellers since the age of the ocean liners, and their staff read an accent from across the lobby.

If you would rather look at pictures than at shop windows, begin an afternoon in the courtyard of the Royal Academy on Piccadilly, then cross the road to Fortnum's for tea. Neither asks anything of you except a little time, and both make a better opening to an evening than a hotel room with the television on.

American visitors tend to dress half a step below London. In the clubs and older dining rooms of St James's, a jacket is still expected and a tie often is. In the newer Mayfair restaurants, a good jacket with an open collar is right. Sneakers, as you would call them, belong to daytime and to other districts.

Your companion dresses for whichever room you name. Tell Octavia the restaurant and she briefs her; the formal plus one covers evenings that ask for black tie, and the Notebook's page on the Ritz explains the most famous code in town.

Nancy is sunny and unhurried, and first-time guests tend to relax within a minute of meeting her; she is among our blondes and happiest at a sushi counter, which surprises visitors who packed for roast beef. Thea, relaxed, punctual and green eyed, is Octavia's suggestion for anyone new to London, and likes a stroll through the park after dinner. Michelle, warm and easy to talk to, has a museum-goer's patience and a sailor's knots, and turns an afternoon into an evening without apparent effort.

Any of them can be booked through booking, from the United States before you fly or from the hotel once you land. Every length, with its price, is listed on the rates page.