You have to practice your chords!
Training your ears to recognize them.
I get asked all the time, "How do you hear the chords so quickly?" The simplest, most basic answer I can come up with is, "I was able to train my ears at a young age - to hear chords simply because I had no other way of learning my favorite songs." When I was learning how to play the guitar as a teenager in the 1970's, the internet didn't exist, and neither did thousands of websites with thousands of songs resourced and catalogued to allow me to take the guesswork out of learning how to play them.
No. I didn’t have access to the internet in the 1970’s.
In many ways, not having easy access to hundreds of thousands of songs with chord charts forced me to be creative. Necessity is the mother of invention; and when you need to find a way to learn how to play music on the guitar, inventing ways to do this is all about being resourceful and creative.
I couldn't afford to buy dozens of song books as a kid. In fact, the music store where I took my guitar lessons had a rather sparse collection of song books for me to choose from. Most of the music books in the display were old, outdated, antiquated music I'd never even heard of.
I did however, have two books: Elton John's greatest hits and Jim Croce guitar songs. I eventually found the "Frampton Comes Alive!" songbook at a shopping center, but it turned out to be a beginner book with mostly wrong chords.
So, how did I figure out a way to learn songs without any songbooks?
I recorded everything I could onto cassette tape. If I was able to capture even part of a song from the radio, it was usually enough for me to figure out the chords. I would listen to the same song, over and over and over - and I would write them out in a spiral notebook. I wrote out every chord I could figure out. This was how I learned to "chart out" songs.
How did I actually know which chords were in the songs? The "Process of Elimination" method. If you're listening to a song and you’re trying to figure out which chords are being played, eventually you're going to stumble upon one of the correct chords. Chances are, it's going to one of the chords you already know. This is where you would need to know exactly how every single one of the chords you play on your guitar, sounds when you play it. You quite literally must learn to take ownership of the music that comes from your guitar.
Okay, so let's say you can hear that one of the chords in the song is an open-string "C" chord. You've played that chord a thousand times. You know that chord very well. Now, you need to figure out the rest of the chords, but what should be your next approach? Well, the "C" chord belongs in three different keys: The key of C major, F major and G major. Each of those keys share several common chords. Let's take a look.
C major = C, Dm, Em F, G and Am
F major = F, Gm, Am, Bb, C and Dm
G major = G, Am, Bm, C, D and Em
Right off the top we can see quite a few common chords:
Key's C and F have "C, Dm, F and Am"
Key's C and G have "C, Em, G and Am.
Key's F and G have "Am and C".
We now have a total of the original six chords in the key of C and four secondary chords from key's F and G:
“C, Dm, E, F, G, A, Gm, Bb, Bm and D”
Now comes the process of elimination. We already know that one of the chords in the song is "C". After listening to the song a few more times, we've discovered that there are two other recognized chords. One of them is Am and the other is D.
So, which key should the remaining chords in the song come from? We've eliminated the obvious keys of F and C because the "D" chord does not belong in either one of those keys. The only obvious key is the key of "G".
Recognizing common chord progressions.
It also helps to remember that many thousands of songs use the exact same chord progressions. One of the most common is the "I - vi - IV - V" or in the case of the key of G major: G, Em, C and D. (Otherwise known as the Taylor Swift chords).
If you apply this progression to the key of C major, the chords will be: "C - Am - F and G". Think in terms of anticipating the obvious direction of the song. Which chords sound best when played together? Chances are, you probably won't use the 7th chord (diminished) in the key as it is a low percentage "transitionary" chord. This leaves you with three major chords and three minor chords for all twelve keys.
You must practice your chords every day and get to know each of them intimately. I have been telling my students for many years to record every practice session they do. Everyone has cell phones with sound recorders built right into the applications by default. USE IT!!!
Record yourself so you can play it back and critique the way you sound, the way you play, where your strong and weak parts are, and train your ears to listen for every nuance, every little feature or mistake you make, and learn how to correct them. Training your ears is a long, tedious process that can take many years to realize. It is my suggestion that you record yourself and listen as a daily ritual every time you pick up your guitar.