User:Wavelength/About English/Commas

• Comma
• MOS:COMMA

There can be confusion between a parenthetical phrase preceding a noun phrase subject and a parenthetical phrase following a noun phrase subject, when the parenthetical phrase is a noun phrase.

• An expert philatelist, John Smith correctly identified the postage stamp.

(An expert philatelist is a parenthetical phrase, and John Smith is the subject.)

• An expert philatelist, John Smith, correctly identified the postage stamp.

(An expert philatelist is the subject, and John Smith is a parenthetical phrase.)

Careful attention to pausing is important.

There can be confusion between participial expressions in sentences like these.

• John Smith, being an expert philatelist, correctly identified the postage stamp.

(John Smith is the subject, and being an expert philatelist is a parenthetical expression.)

• John Smith being an expert philatelist, William Brown showed him the postage stamp.

(John Smith being an expert philatelist is a parenthetical expression, and William Brown is the subject.)