Idiomatic Usage: grounds for

grounds for (something)

The basis for some action or decision, often one that is disciplinary or legal in nature.

• Be careful now—plagiarism is grounds for expulsion.
• Your negligence is grounds for a lawsuit. 
• Is infidelity grounds for divorce in this state?

introduce to vs. introduce into

introduce to: to present someone to someone else for the first time so that they can become acquainted

• I would like to introduce you to my cousin, Sarah.
• We proudly introduce to you the Dutch team.
• Let me introduce you to him.

introduce into: to put something into use for the first time, or to put something into a new place

• New computers have been introduced into the office.
• The grey squirrel was introduced into Britain from North America.
• Fuel was introduced into the jet pipe.

Rates for vs. Rates of

When rates means prices charged, it should be followed by for instead of of

State officials report that soaring rates for liability insurance are forcing cutbacks in the operations of everything from local governments and school districts to day-care centers and recreational facilities. - correct

State officials report that soaring rates of liability insurance are forcing cutbacks in the operations of everything from local governments and school districts to day-care centers and recreational facilities. - incorrect


When rate is used as a standard of measure, it should be followed by of instead of for

High rates of sick leave are a concern for all types of organizations. - correct

High rates for sick leave are a concern for all types of organizations. - incorrect

Known to vs. Known as

Known to: when we want to talk about some fact that people have learned.

• Lions have been known to occasionally kill large beasts like elephants, giraffes, and rhinos.
• Elephants are known to communicate with seismics, vibrations produced by impacts on the earth's surface or acoustical waves that travel through it.

Known as: when we want to talk about the name of somebody or something or its definition.

• Some male Asian elephants are tuskless and are known as Muknas
• Lions are big cats known as the "King of the Jungle".