The major focus of English classes in Thailand is grammar. The official Thai core curriculum places emphasis on grammar.
This lesson was a review of when to use the word "since" and when to use the word "for."
The young novice copy the sentences off the board, and then are to make the correct choice between "since" and "for." Even though I wrote the sentences on the board, I, a native speaker, found it challenging to know which word to use.
Can you imagine what it is like for these young Thai novice?