`10`.It is difficult to learn Japanese

`\rightarrow` It is ( not ) + adj + to do sth : Như thế nào để làm gì

`11`.They were playing tennis at 10.30 yesterday morning

`\rightarrow` Thì QKTD : S + was / were + V-ing

`\rightarrow` Đặc điểm nhận dạng : at 10.30 yesterday morning

`12`.We were delighted to get your letter yesterday

`\rightarrow` be delighted + to do sth : Vui mừng vì làm gì

`13`.The streets are cleaned by the workers everyday

`\rightarrow` BĐ `-` Thì HTĐ : S + is / am / are + V3 / PII ( by O )

`14`.The celebration will be held tomorrow

`\rightarrow` BĐ `-` Thì TLĐ : S + will be + V3 / PII ( by O )

`\text{# Kirigiri}`