Period .

Two spaces follow the period after
an ellipsis . . .. That’s it.

• At the End of declarative and an imperative sentence

  Examples

  The sentence ends a sentence.
  Tell me your name.
  
  
• After an indirect question

  Example

  She wondered where she forgets her suitcase.
  
  
• At the end of a polite request that sounds like a question

  Example

  Could you see this photo.
  
  
• In abbreviations

  Example

  U.S., Inc., Co.
  
  
• As a decimal point

  Example

  4345.67
  
  
• In front of the last quotation mark

  Example

  She said, “You are right.”
  
  
• Outside parenthesis when they enclose only a word or fragment

  Example

  Phrasal verbs contain verbs and prepositions (see the appropriate chapter).
  
  
• Inside parenthesis when they enclose a complete sentence

  Example

  Phrasal verbs contain verbs and prepositions (they are separable or inseparable.)
  
  
• In enumeration and only after complete sentence in list

  Example

  She needs the following:
  1. Books and newspapers
  2. The dog must be in the garden.
  3. Silence
  
  
  
• To end figure captions even if not they are not complete sentences

  Example

  Figure 13. Differential Cross Section and Radial Dose.

Ellipsis is the series of three periods. It indicates the omission 
of some words in a direct speech. (It contains three periods and 
four spaces.) 
he declare, “Everything is all right . . ..”