what is difference between but and yet
As conjunctions, 'yet'’ and ‘but’ are similar. Both are used to show contrast or comparisons. However, 'yet' is used when there is an element of surprise involved in the comparison or contrast. That is, 'yet' has a stronger effect than 'but', and so, it is used when the part coming after the conjunction is of an unexpected nature.
I worked hard, but I did not score well in the exam.
In this sentence, we find a contrast in the sense that even though I worked hard, I did not score well in my exam. There is no element of surprise involved.
Let us take another example:
He was not well, yet he won the wrestling match.
In this sentence, there is an element of surprise present: He managed to win the match in spite of being unwell.