There are basic rules like don't wear white or forget to RSVP, but if you haven't been to a lot of weddings, there may be some etiquette rules you're unfamiliar with.
Narcity spoke with an etiquette expert, Susy Fossati, the director of Avignon Etiquette, an etiquette consultancy in Toronto, and she shared some of her tips for weddings so you can make sure you're ready for the big day.
Here are nine etiquette rules you should follow at weddings, according to an expert.
When should you respond to RSVP?
A stack of mail.
Once you receive an invite to a wedding, the clock is ticking!
Fossati says you should respond to an invitation as soon as you receive it unless you are unsure that you will be able to attend, and even so, you should respond by the deadline and let the couple know that you are uncertain.
So don't let a wedding invite sit in your drawer for months only to RSVP the week before.
The couple has to order you a plate of food and plan accordingly for how many guests they can expect.
Are you expected to bring a date to a wedding?
If your invitation didn't say plus one, don't bring a date!
Fossati says that unless you are explicitly asked or told you can bring a date, then you shouldn't.
If you weren't given a plus one, but you'd like to bring a date, you'll have to clear it by the couple.
But chances are they didn't give you one for a reason. Maybe they don't know your partner well, or they're just looking to have a smaller wedding.
Fossati says you can reach out to clarify by saying something along the lines of "I just want to make sure that the invitation was for myself only and not myself plus a guest."
If they say yep, it's just for you, leave your date at home!
Are kids supposed to be at weddings?
Kids are lovely balls of sweetness, but they are also loud, messy and tend to cry at inopportune times.
Whether someone wants kids at their wedding is a personal choice, and just because you are invited to a wedding doesn't mean your kids are too.
Fossati recommends finding out in advance if children are welcome at a wedding before letting your tots tag along.
So if you're invitation doesn't explicitly say kids are welcome, you should ask the couple for clarification.
What do you wear to a wedding as a guest?
Apart from obviously not wearing white, Fossati says you should dress for the occasion.
"For the most part, weddings are formal, if not semi-formal events and should be approached tastefully," she says.
"There is nothing wrong with wearing something that makes you feel beautiful and your best and that is playfully sexy — like an open-back dress or a skirt with a modest slit, but avoid anything that draws excessive attention in the presence of other guests and small children."
So to sum that up, don't dress like you're going out for a night on the town in Las Vegas – unless that's the theme.
Is it OK not to bring a gift to a wedding?
A pile of gifts.
If you are attending a wedding, you should bring a gift.
Fossati says the most important things to consider are how close you are with the couple and how much money you can afford to spend on a gift.
If you are going to multiple wedding events like an engagement party, bridal shower and wedding, she suggests following the 60- 20-20 rule for gifts.
"The 60-20-20 rule suggests that if you are attending more than one formal event, you can spread out your budget accordingly, i.e. 20 percent on the engagement gift, 20 percent on the shower gift, and the remaining on the wedding gift."
Who should give a speech at a wedding?
A mic on a table.
The only people who should stand up and clink their glasses at a wedding are people who have been invited to speak.
Fossati says it's a bad idea to go rogue at a wedding and share an impromptu speech toasting the bride and groom because chances are you're going to derail a perfectly timed event.
"The flow of a wedding is very important and monitored. Ask any wedding planner. If you feel the need to say something, consider asking to do so at less formal events if you are attending. For example, the rehearsal dinner."
If you can't squeeze in a speech at one of the B-list events, she suggests sharing your sentiments with the happy couple in a private moment when you have a chance.
How long should a speech be at a wedding?
Glasses of champagne.
No one needs to hear a 30-minute spiel on the dirty details of that one wild spring break in Cabo.
Fossati says a speech should be classy and quick, so stick to the happy highlight reels and hit your points home fast.
"A toast is not a speech. The rule of toasting are 3 Bs - begin, be brief, and be seated. If you are giving a speech, keep it tasteful, under five minutes and something that both the bride, groom, and guests will appreciate."
What can you do with your phone at a wedding?
A person with their phone out at a wedding.
Put your phone away!
Weddings are a time to be present, and accoridng to Fossati, you shouldn't be on your phone.
"For any formal events, the use of phones or any electronics at the table should be strictly prohibited. Consider taking photos during the cocktail hour or when the party begins."
So during the ceremony, maybe tuck your phone away and let the photographer capture all the special moments.
Is it rude to get drunk at a wedding?
A bottle of alcohol being poured into a martini.
You never want to be the drunkest person at a wedding.
That badge of debauchery is reserved for embarrassing uncles and overly emotional family members of the couple.
According to Fossati, you should only drink what you can handle.
"Everyone knows their limits. While one or two drinks may be a good start for someone, it might be all another person can handle. Drink responsibly so that you don't embarrass yourself, or worse, put yourself in a situation that you will regret later on."
This interview has been condensed and edited for clarity.
A part of the wedding speech Reddit thread. 
A part of the Reddit thread about postponing the wedding.