Here are some ways you can tell the age of your piece

The Mckinley Tarriff act of 1891 required that the name of the country where the ceramic was originally made must be printed on each piece, sometimes country names were used as part of the mark before 1891, below are dates of the earliest marks using the country name as part of the mark.

China: c:1900

Czechoslovakia 1918

Danmark(Danish for Denmark) c:1850

Denmark C:1890

England 1880

Finland 1897

France 1867

Germany 1885

Hungary 1935

Japan 1921

Norge (Norwegian for Norway) 1911

Norway 1935

Portugal 1835

Sweden 1935

Switzerland 1906

United States of America 1935

Below are some terms/words used on pieces that can give you an idea of dating if they appear on your piece, These are by no means all the terms or marks used on items but are some that can help 

Nippon(Japan) 1891-1921 After 1921 The United States did not recognize the name Nippon any longer and that is the year Japan started being marked on items.

Bone China: Not used as part of a mark until about 1915

Copyright: After 1858 to present, The earliest the whole word was used is 1892

Copyright reserved After 1876

Delft 19th-20th Century

Detergent Proof C:1944-Present

Dishwasher Safe After 1955

East Germany 1949-1990

Incorporated c:1940

Limited(Ltd) After 1861

Made in Occupied Japan 1945-1952

Oven Proof After 1933

Oven Tested c:1935

Oven-To-Table 1978-Present

Patent Applied For 1902-Present

Patent Pending 1940-Present

Patented 1900-Present

Reg. U.S. Pat. Off. C:1932-Present

Reg. Rd. Registered with a number 1884 Present

Registry Mark Diamond Shaped 1842-1883 English designation that indicates a design or process has been registered

Semi-Vitreous(s-v) After 1901

Trademark: After 1862 usually after 1875. Word used on English pieces after the Trademark act of 1862 used on United States wares after 1875

22 carat term used after the 1930's

Underglaze C:1903-1945

Union made 1930's

U.S. Patent After 1900

U.S. Zone U.S. Zone germany 1945-1949

West Germany 1949-1990