In English, the words "that" and "so" are often used to increase the extent of an adjective (ex. "he is so tall" or "this food is so good"). In Chinese, 那么 (nàme) and 这么 (zhème) serve the same function.

Structure

All you have to do to use this grammar structure is put the 那么 or 这么 in front of the adjective.
Subject + 那么 / 这么 + Adjective

Examples

Zhè zhǒnɡ píjiǔ zhème hǎohē!
这 种 啤酒 这么 好喝!
This kind of beer is so good!

Nǐ zěnme zhème piàoliɑnɡ!
你 怎么 这么 漂亮!
How can you be so beautiful!

Tā nàme ɡāo!
他 那么 高!
He's so tall!

When to use which one
You might be thinking "那 and 这 have different meanings. How can they be used the same way?" Well, there are some differences. "这么" is used when the thing you are talking about is close by, when you would say "this" or "这个". On the other hand, if the object is far away, you would use "那么". Furthermore, this distance doesn't have to be physical, it can also refer to time, so you would use "那么" with things like "yesterday" or "tomorrow".