Question

the lesson is too difficult for the students to understand( combine using so that​

Answer 1

The lesson is so difficult that the students cannot understand it.

• Firstly, for any such transformation, we need to keep the tense same. In this case, it is in the present tense.
• The 'so...that' is used as a subordinating conjunction,i.e. it links an independent clause to a dependent one.
• It is used to combine clauses so as to indicate a 'cause and effect' relationship in the sentence.
• Other examples-

1. The sum is so difficult that I cannot do it.
2. He was so weak that he could not walk.