Language. Bengali is the state language and is spoken by almost everyone. Hindi is widely understood, and English is common in hotels, restaurants and among educated Kolkatans — the city has a strong English-language tradition. Communication is rarely a problem. "Nomoshkar" (hello) and "dhonnobad" (thank you) are appreciated.
Kolkata is a walking city. More than Delhi or Mumbai, the way to experience it is on foot — the architecture, the street life and the neighbourhood texture only register at walking pace. Wear proper shoes and accept uneven pavements.
Howrah Bridge photography. The bridge is designated a sensitive structure and photography from certain points is officially restricted. Be aware of signage and don't assume it's fine. Views from the ferry are both legal and better.
Which station? Howrah and Sealdah are on opposite sides of the river and a long way apart. Check your ticket carefully and allow substantial time if you need to get between them.
Durga Puja planning. If visiting during the festival, book accommodation months in advance, expect prices to rise sharply, and accept that moving around will be slow. Go to Kumartuli beforehand. Wear comfortable shoes. It is worth every inconvenience.
Kalighat temple caution. As at many major pilgrimage temples, unofficial "guides" and priests may attach themselves to you and demand substantial payment. Be polite but firm, agree any amount in advance, or decline assistance entirely.
New Market touts. Persistent and numerous. A firm, repeated "no thank you" works; engaging in conversation does not.
Food safety. Kolkata street food is excellent and generally safe from busy stalls with high turnover. Puchka and kathi rolls are worth trying. Avoid raw items and standing water, and stick to sealed bottled or filtered water.
Waterlogging in monsoon. Streets flood quickly and can become impassable during heavy rain. Don't schedule tightly between June and September, and be prepared to change plans.
Air conditioning and temperature swings. Interiors are often aggressively cold while outside is hot and humid. A light layer helps.
Money. ATMs widespread, cards accepted at established businesses, UPI dominant. Carry cash for street food, taxis, markets and ferries.
Bargaining. Expected at New Market, Gariahat and street stalls; not in emporia, malls or restaurants.
Politics and conversation. Kolkatans talk about politics, film and football with real seriousness and enjoy debate. Engaging is welcomed; being dismissive is not. Football rivalries (Mohun Bagan and East Bengal) are taken very seriously.
Connectivity. Good coverage across the city. Buy a local SIM on arrival with passport and visa copies plus a photo.