Please check the following sentences. Are the underlined part in each sentence acceptable?
1. Midsummer’s Night is celebrated in Scandinavia whit huge parties that go on all night.
2. Wearing baseball caps backwards was so popular that everywhere you went you saw people wearing them that way.
3. The Olympic skier should had paid more attention to the snow conditions. He fell.
4. Only in the last few days did the idea of moving to a small house made sense.
5. The biggest buildings in the world were under construction, but none so gargantuan as those Gillette projected.
Only 3 is wrong.
3. The Olympic skier should have paid more attention to the snow conditions. He fell.