An important and useful particle is -보다. With it, you can easily make a comparison between two persons, objects, etc. It is pretty easy to use, though you need to be aware of how it actually works nonetheless.
As mentioned, the particle -보다 is how you can make a comparison between two persons, objects, etc. In general, it always means that the subject is more in certain regard than the word with the particle. If you want to say the opposite without switching the particles used, you will need to use the adverb 덜 (less) to explicitly state that the subject is less in certain regard than the particle with -보다.
가: 오늘 날씨가 좋네요.
나: 네, 하지만 어제보다 덜 따뜻해요
A: The weather today is really nice.
B: Yes, but it is less warm than yesterday.
How To Use
-보다 is a very simple particle to use. Like for particles like -밖에, -쯤, -만, etc., you needn’t worry about vowels or consonants. You simply attach the particle to the word and you are done. You simply need to keep its meaning in mind and how it functions.
As mentioned earlier, the particle -보다 means that the subject of the sentence is more in certain regards than the word with the particle. However, if you use the adverb 덜 (less), the meaning becomes opposite and the subject is less in certain regards than the word with -보다. You can also use the adverb 더 (more), but this is not a necessity and generally emphasizes what you want to say.
Lastly, the order in which the subject and the word with the particle -보다 appear is not important. Whether the subject comes first or after the word with the particle, the meaning remains the same. However, there is a preference to have the subject first as this is clearer.