The unfamiliar phrases could possibly mean:1. "What sauce is with the nigiri?" - This suggests that there is a type of sushi called nigiri that is served with a specific type of sauce or condiment. The person is inquiring about which sauce is served with the nigiri.2. "Can you grab the check?" - This means that the person is asking someone to go and get the bill or check at a restaurant or establishment to settle the payment.3. "Do you take reservations?" - This is a question asking whether a restaurant or business accepts reservations or bookings in advance. It is commonly asked when someone wants to secure a table or spot at a specific time.4. "What are the soup du jour and the salad bar?" - This sentence refers to two different options at a restaurant. "Soup du jour" is a French phrase that means "soup of the day" and indicates that the restaurant offers a specific soup that changes daily. The "salad bar" refers to a self-service area where customers can build their own salads with a variety of toppings and dressings.5. "Is it all-you-can-eat or à la carte?" - This is asking about the dining option available at a restaurant. "All-you-can-eat" means that customers can eat as much as they want from a designated menu or selection of dishes for a fixed price. "À la carte" means that customers can order individual dishes separately and pay for them individually.