]Not until] I only recognized him when he took off his hat.

[Distance] How far is it from Ha Noi to Sapa?

[Necessary] You needn’t hurry. There’s still much time left.

[Unless] You will catch a cold if you don’t keep your feet dry.

[When] On arrival at the shop, the goods are inspected carefully.

[If] The accident happened because the train driver ignored the warning light.

[Advised] “You should take more exercise,” the doctor said, “if you want to lose weight.”

[Eye] “Could you guard my handbag while I go to the toilet?”

The thief has broken into his house three times recently.

[Getting] He is finding it easier to work on night shift.