The basics: A retrograde occurs when a planet appears to be moving backwards from our vantage point here on Earth. It isn't actually moving backwards, it just appears that way. Mercury turns retrograde most often because it's nearest to us, about 3-4 times per year, and lasts for several weeks. When a planet retrogrades, what that planet rules tends to be thrown off, along with what the sign it's retrograding in rules.
With Mercury retrograde, we experience a shadow and a storm. The shadow period starts when Mercury first hits the point in the zodiac it will turn direct at, and ends when it last hits the point in the zodiac it will turn retrograde at. Most people don't feel the effects of Mercury retrograde until it enters the storm period though.
The storm period of Mercury retrograde is when Mercury is moving at its slowest, less than 40 minutes per day. Mercury is a fast-moving planet and hates it when he's moving slowly. There's usually two storm periods, one around the time Mercury turns retrograde, and one around when it turns direct.
The shadow of this Mercury retrograde begins May 4th and ends June 27th. The exact retrograde begins May 18th at 9:49PM ET and ends June 11th at 6:33PM ET.There is just one long storm period for this retrograde, beginning May 12th and ending June 21st, so there’s no break this time.
This Mercury retrograde occurs entirely in air sign Gemini, which is one of the signs that Mercury naturally rules, so things are really going to get wild, baby. Both Mercury and Gemini rule communications, so that’s double the retrograde fun there. We really have to be careful what we say, but boy, we’ll probably be sticking our foots in our mouths a lot! We need to think before we speak, but even our thinking isn’t so hot right now. Patience and understanding, patience and understanding - that’s what we need!
Young people can be in the spotlight, and they can cause more problems, create more uprisings, and we can see more issues with things that impact them most, like education. Our communities can have problems, and we don’t communicate with our neighbors, feel out of touch with our neighborhoods, or want to detach from them.
Our minds can be extra active, and we have lots of ideas, but need to press pause before we take off running with any of these ideas. Seeing the details can be a struggle, which leads to problems later. If it’s something than can be completed quickly (during the retrograde), then it can be okay, unless it’s something that will have long-term impact. Then it might be dicey.
We can also see electronics (mostly the stuff we use daily), the devices we use to communicate on a regular basis, and transportation that we regularly use impacted during this retrograde. More car problems, delayed bus schedules, cell phone glitches, etc.
The Mercury retrogrades this year occur in the air signs, which are social signs, so we can find that in general, we have a harder time getting along, being sociable, and relating to one another. These are also the signs of the mind, so Mercury retrograde will screw up our communications even more this year.
This Mercury retrograde makes 3 major aspects while in retrograde, a conjunction (in the same spot) to Mars on May 27th, a square (hard aspect) to Neptune on May 29th, and a sextile (easy aspect) to Venus on June 10th.
The conjunction to Mars can make us get into more fights, be more defensive with what we say and share, and we have to work on controlling our tempers. The square to Neptune can make us out of touch with reality, a little delusional (hey, that be fun sometimes!), and we have a hard time focusing on reality and details and practical things.
The sextile to Venus occurs the day before the end of the retrograde, so this energy is felt around the turn direct, and we can work on trying to smooth things over quickly as this retrograde ends. The retrograde begins sextile Jupiter, so the start and end energy isn’t so bad, though we may be prone to laziness.
The turn retrograde begins at 13 degrees Gemini, so those of you Geminis born June 3rd - 5th may feel the turn retrograde most. The turn direct occurs at 4 degrees Gemini, so those of you Geminis born May 25th - 27th may feel the turn direct most.
For the rest of you, check the house(s) Mercury will be retrograding in of your own natal chart, and any aspects Mercury will make during its retrograde to your natal planets, to fully understand how it will impact you personally.
If you have Mercury retrograde in your natal or progressed chart, you may not feel the worst of this. Those individuals generally don't experience the difficulties of the retrograde because it feels more natural to them. Of course, chances are everyone else around them doesn't have the same aspect, so they can still experience difficulties brought on by others.
Suggested Reading: The Mercury, Venus and Mars Retrogrades page for general interpretations