Is everything shut down in Lisbon over Christmas
 

I am travelling alone to Lisbon for 5 days over the Christmas period 23-28 Dec have booked an apartment but wonder if any restuarants, museums, shops etc, trams will all be open.

We also will be in Lisbon, but from 26 Dec. I understood that only in the Christmas day (25) all museums, palaces, shops are closed.

I have spent Christmases in Lisboa. Christmas Day is a public holiday, but 26 December is not.
Public transport operates a Sunday service, so trains, buses, trams, ferries and funiculars will be running on Christmas Day.
Shops will be closed on Christmas Day, along with many restaurants. There will still be a choice of places open on Christmas Day for lunch and dinner. Some places will have special menus. The Portuguese word for turkey is "peru".
Portuguese people will have a family dinner on Christmas Eve, and very few restaurants will be open then. There are a few places in the city centre which will be open for dinner on Christmas Eve. You might do better to have a big lunch on the 24th, then a snack in the evening.