Cohesion and coherence are similar concepts but not the same. Cohesion refers to the micro-level of the text, the logical connections between words and sentences that give a sense of flow. Coherence refers to the macro-level of the text, the sense that the paragraph or block clearly communicates an idea to the reader. You can use several techniques to ensure that your paragraphs are cohesive and coherent.

• Exploit repetition
  
  One way to make text cohesive is to repeat words, to repeat ideas using different words (synonyms) or to refer back to previous ideas using pronouns or shell nouns (see example text below). Repetition, particularly of characters in subject position, and constant reference back to previous information gives text a sense of unity and focus.
  
  
• Use transitions
  
  Transitions are words and phrases that signal relationships between ideas. They can be used to good effect at the beginning of sentences to make text flow but, be careful, they cannot replace good organization. One of the dangers of transitions is to use too many of them.  
  
  

  Addition	Cause/effect	Sequence
  Also	Because	First/In the first place
  Again	Since	Second/In the second place
  Then	Thus	Third
  In addition	As a result	Next
  Moreover	Therefore	Finally

  
  
  

  Contrast	Example	Summary
  In contrast	For example	To conclude
  However	For instance	To sum up
  Although	By way of example	In conclusion
  Despite	In this case	In brief
  On the other hand	Namely	In the final analysis

  
  
  
• Move from old information to new
  
  Text is more readily understood if writers begin their sentences with old or familiar information and then go on to add something new or unfamiliar. The old/familiar information comes from two sources: (a) the sentences readers have just read, and (b) readers’ knowledge of the subject. This principle goes hand in hand with the principles of characters as subjects and end focus. As soon as writers have stated their main characters (normally towards the beginning of the text), readers will accept them as familiar information, so when characters are regularly placed at the beginning of sentences, the information naturally flows from old to new.