Look over these sentence fragments. 

The drunken face of McCarthy mocking people.

Because the river is rising.

Although there may have been two gunshots.

Some to jail, some into exile, others into insane asylums.

What makes these fragments is their lack of a main verb. Without a verb, these fragments cannot describe a complete action. Instead, they are subordinate clauses -- words that take orders instead of giving them.

Look for the connecting word which might join the fragment to an independent clause:

We need more sandbags because the river is rising.

Although there may have been two gunshots, most people still believe Oswald killed Kennedy.

Change the participle (-ing) to a main verb:

The drunken face of McCarthy mocks people.

Use the fragment as a participal phrase:

The drunken face of McCarthy mocking people is a lurid reminder of a bad time in American politics.

Or simply insert a main verb:

After the trials, people seemed to disappear: some to jail, some into exile, others into insane asylums.

Sometimes, in descriptive writing, verbless sentences can be effective:

Nice to see living things that don't know anything about future troubles or death of Committees. (Hellman, 92)

You dirty rat!

A day of dappled, sea-borne clouds.... (James Joyce, A Portrait of the Artist as a Young Man)

In such sentences, the main verb is understood, and the author is trying for the effect of words spoken in the head -- thoughtful, angry, shocked, or bemused. The writer of such verbless sentences should use them both sparingly and intentionally, taking careful note of their effect in a whole passage.

   Sentence Fragments
   Comma Splices
   Run-on Sentences
   Dangling or Misplaced Modifiers
   Subject-Verb Agreement
   Split Infinitives
   Which, That, It, and Of
   Semi-colons and Colons
   Apostrophes
   His and Her