` ->` My brother doesn't like ice-skating because he thinks it's dangerous.

` -` HTĐ ` (-)` S + do/does + not + V-inf + ...

` -` HTĐ ` (+)` S + V-inf/es/s + ...

` -` HTĐ be ` (+)` S + is/am/are + ...

` -` because + clause: bởi vì

` ->` Traveling by train, bus or bike is much cheaper than traveling by plane.

` -` by + phương tiện: bằng cái gì

` -` So sánh hơn: S + V/be + tính/trạng từ so sánh + than + S2