Native English speakers tend to use strong language, so one step towards communicating naturally is to adopt a stronger style.
In casual water-cooler chats, native speakers often use this pattern: "[Subject] is so [adj] that [full sentence]."
- It's so hot that you can fry an egg on the sidewalk!
- I'm so busy that I barely have time to sleep!
- I'm so tired that I feel like I'm sleepwalking!
Notice that the full sentence is something that is not real, but feels like it might be real. You can't really fry an egg on the sidewalk, you do have a little time to sleep, and you are not really sleepwalking.
If your example is real, then "that" cannot be used. Simple say the full sentence that is true, "It's so hot! I think it's almost 40 degrees!" Or, "I'm so busy; I only slept a few hours last night."
Using "that" can also be done as a joke. Check out some of these:
- It’s so hot that all my bread has turned into toast!
- It’s so hot that now hot water comes out of both taps!
Metaphors, jokes and strong language are very common in spoken English. Even if you don't use it yourself, understanding this style is a big step towards watching movies without subtitles or hanging out with groups of native English speakers. If you can use this, it's very impressive. Try one in your next class!
water-cooler chat [n]— casual conversation at the office, usually in a common area like the lunch room, elevator or around the water cooler.
hang out [v]—spend time with friends without doing a special activity, often done at a bar, cafe, mall, park or someone's house.