Gerunds ( = -ing)

We use the -ing form of a verb:
 
 * As the SUBJECT of a sentence:
Eating vegetables is healty
Studying is an important part of your responsibility.
 
   * After PREPOSITIONS:
I am tired of wasting time
She kept on trying

   * After some VERBS; for example:
like, enjoy, dislike, love, practise, avoid, recommend, suggest
Examples:

She really likes reading at night
She suggested going for a walk
They avoid repeating words in their writing exercise
They recommended trying that new restaurant
They practise playing the piano twice a week

To infinitive

We use the full infinitive:
 
 * After an ADJECTIVE:
This mobile phone is easy to carry
That film is nice to see
   
  * To express PURPOSE
Use this device TO clean the screen
I need  a printer TO print this document.

     *after some VERBS:
 learn, want, plan, need, decide.
 I want TO buy a new sweater
She is planning TO go on holidays to Brussels.
We decided TO organise a  school trip
I learned TO drive when I was eighteen.