How can a teacher of English motivate students to participate in the educational situation to achieve the hoped objectives of the educational process?

A teacher should ask questions to students from time to time and encourage them to think and come up with their a own questions, Until and unless the students think, they won't be able to participate in the learning process.

There is a general thinking about learning something in the students that its hard. Some students take it light but others burden it on their nerves. 

To remove this concept psychologically, teacher should start from a simple and easy task / lesson. When the students start to do it then only he should move towards more complicated ones. This phenomenon creates a realization in the students that it is not so hard as we thought and they start taking interest in the educational activities. Teacher should never forget to appreciate the achievements of his students whether minor or remarkable.

Try to see the curriculum from their point of view. It's a bunch of paper chaining them down to the desk, asking them to memorize, and then recite what they've learned. For some countries it's actually not a requisit for them to understand. I suggest reading the first chapter of a book called "The Phantom Tollbooth" by Norton Juster to get a small incite to how they view the educational system.

The solution comes from the teacher. Ask yourself an important question: How do YOU view the ciriculum being given. Children are very impressionable and look to the teacher's reactions as they would their parents. If you view the ciriculum as stiff and unflexible then you have a boring subject and you lose the concentration of the children. If you find the ciriculum as a way to show the children a bit of how the world works, they will not only listen, but begin to ask and discover for themselves more of what you are giving them.