Say birkat ha'mazon if you ate a “meal” as defined by halacha—that is, if you ate at least 1.3 fl. oz. (39 ml, or 1/6 cup) of bread made of the Five Grains within four minutes.

Three Shabbat Meals
We are required to eat three Shabbat meals, as a rabbinic (d'rabanan) enactment to enjoy Shabbat (oneg Shabbat). The first Shabbat meal must be at night and the remaining two must be during the day (the third meal must be eaten after halachic midday). Friday night dinner and the first meal on Saturday are preceded by kiddush. For the first two Shabbat meals, say ha'motzi over two complete loaves of bread, each of which is at least 1.3 fl. oz. in volume. For the third meal, the ideal is to use two complete loaves of bread, but the requirement of eating the third meal can also be fulfilled by eating any food other than salt or water.

Source of Saying Shabbat Kiddush

• Saying kiddush on Shabbat night is a commandment from the Torah (d'oraita).
• Saying kiddush on Saturday morning is a rabbinical (d'rabanan) enactment.

Note If you did not say Friday night kiddush, you must say that version of kiddush on Shabbat morning and it is then a requirement from the Torah (d'oraita). Do not begin with va'yechulu; instead, begin with borei pri ha'gafen and say the second blessing of kiddush.

Source of Kiddush Location
Saying kiddush at the place where you will eat your meal is a rabbinical (d'rabanan) enactment.

Shabbat Kiddush-Meal Quantities: Evening

• For evening kiddush, a minimum of 4 fl. oz. (119 ml) of wine must be blessed on and at least half must be drunk.
• For the evening meal, as on Shabbat lunch and all required Jewish festival meals, a minimum of 1.9 fl. oz. of bread must be eaten within four minutes.

Shabbat Kiddush-Meal Quantities: First Meal on Saturday
Shabbat day first meal has two separate eating requirements.  They may be combined (say/hear kiddush and start the main meal right away) but are often done separately (say/hear kiddush and then eat some mezonot; the main meal is eaten later in the day).
Note Since eating and drinking requirements on all morning kiddushes (both Shabbat and Jewish festivals) are d'rabanan, the required beverage amount for morning kiddush is only 3.3 fl. oz. (99 ml) instead of the d'oraita 4 fl. oz. (119 ml), which is required for kiddushes for Shabbat evening.
1) Morning kiddush requires a halachically legal “meal” with these elements:
      a) Blessing on a minimum of 3.3 fl. oz. (99 ml) of wine (or other beverage),
      b) Someone's drinking at least 2 fl. oz. of the beverage, followed by
      c) Eating at least 1.3 fl. oz. (39 ml, or 1/6 cup) of some type of mezonot (or bread) within four minutes.
Note If you drink at least 3.3 fl. oz. (99 ml) of wine within 30 seconds, you do not need to eat mezonot.
Note You do not need to drink the wine or other kiddush beverage to fulfill “establishing a meal.” You may hear kiddush and then simply eat the required amount of bread or mezonot. This applies to Shabbat or Jewish festivals, evening or morning.
The kiddush “meal” does not have to satiate.
Note If you have not fulfilled the requirements for kiddush, you may not eat other foods, such as fruit or fish at a kiddush.

2) The real meal (kovei'a se'uda) of Shabbat lunch requires eating at least 1.9 fl. oz. (56 ml) of bread (or matza during Passover!) within four minutes. It should include enough food to satiate.
Note You can simultaneously fulfill the requirement to “establish a meal” and to “eat a meal” by eating one (the same) piece of bread.
For details on fulfilling the first two meals' requirements, see Shabbat: Kiddush.

Shabbat: Eating a Meal Requirement: Third Meal
For details on fulfilling the third meal's requirements, see Shabbat: Third Meal (Se'uda Shlishit).

If you fell asleep for more than 30 minutes in the middle of a meal:

• Wash again and say ha'motzi again, and then say birkat ha'mazon, OR 
• Eat other items with a fore-blessing and after-blessing (since your previous eating is finished).

• Say birkat ha'mazon if you are:
  • Finished eating, and
  • Not hungry again, after having been satiated at the meal.
• Do not say birkat ha'mazon if you are
  • Finished eating, and
  • Hungry again (after having been satiated at the meal), as the original snack or meal is irrelevant to any after-blessing now.

If you fell asleep for more than 30 minutes in the middle of a meal:
Step 1: Wash your hands the Three-Times Method to remove the tum'a of your sleep.
Step 2a: To Continue Eating
To continue eating in this case, since the previous blessings and food are no longer relevant (due to hesech da'at), you may:

• Wash again and say ha'motzi again, and then say birkat ha'mazon, OR 
• Eat other items with a fore-blessing and after-blessing (since your previous eating is finished).

Step 2b: If You Are Finished Eating

• Say birkat ha'mazon if you are:
  • Finished eating, and
  • Not hungry again, after having been satiated at the meal.
• Do not say birkat ha'mazon if you are
  • Finished eating, and
  • Hungry again (after having been satiated at the meal), as the original snack or meal is irrelevant to any after-blessing now.

Lashon ha'ra is saying (or communicating in any way--even by rolling your eyes, winking, etc.) anything derogatory or negative about someone that can hurt him or her in any way--by causing embarrassment, loss of money, lowered esteem, bad reputation, etc. 
 
Lashon ha'ra in which you attribute the negative statement about the person to whom you are speaking to someone else is called rechilut (gossip). 
 
Lashon ha'ra that is false is called motzi shem ra. Saying something that is true is not lashon ha'ra if it is being said for a positive purpose (even though the same words would be lashon ha'ra if they were only intended to hurt another person and had no positive purpose).
 
Lashon ha'ra, including rechilut, is forbidden to be said about shomer Shabbat Jews except for a positive purpose; motzi shem ra is forbidden to say about anyone--Jewish or not, shomer Shabbat or not, whether for a positive purpose or not.
 
Speaking Lashon HaRa
 
When You May Say Lashon HaRa
Lashon ha'ra, including rechilut, even if truthful, is not permitted except for a constructive or positive purpose. (Motzi shem ra is never permitted.) Its purpose cannot be to hurt a person.  It is permitted and recommended to tell the facts about someone:

1. To protect others from being hurt (being cheated, molested, etc.), or
2.  For a positive purpose that cannot be achieved through any other means.

 
Lashon HaRa To Protect Others from Being Hurt
You may say truthful lashon ha'ra (including rechilut, if it is necessary to divulge the name of the person who told you):

• To prevent a bad person from telling children bad things or to keep children from learning bad behavior from the bad person;
• To avoid being implicated in what the bad person is doing;

• To prevent other Jews' suffering a loss by using a worker who did bad work for you.

• If a businessman cheats you or lies to you, you should warn other Jews about him (but only if you suspect they want to do business with him).
• If you know something bad about someone who a third person wants to date or marry, in many cases you are required to tell what you know (but this can be very complicated and dangerous and a rabbi should be consulted about what to do in many cases)!

 
When You May Add Facts to Correct Possible Lashon HaRa
If the reasons behind an action are not clear and someone may get the wrong/negative impression of someone in question, then you should tell the facts and tell the entire story. 
Example
Someone (A) insults another person (B) in public. Entire story is that B beat up A previously. Knowing the full story changes how people might view A.
Note If it is only your opinion, state that instead of declaring it as fact.
 
Lashon HaRa To Allow Gain
Saying lashon ha'ra for a positive purpose includes gain for yourself or for someone else; you may talk about others in cases such as these:

• Psychotherapy  You may say truthful lashon ha'ra or rechilut to a psychotherapist since you don't know what is important. Outside of therapy and with non-therapists, you may say anything that will bring about a positive result (and only if there is no other way to achieve that result).

   

• Upset  If you are upset by what a person did to you and it will help you to calm down by telling what was done to you (that is, you will gain by feeling better).

 
Note If you want to ask someone for information that could be lashon ha'ra, you should say why you are asking so the other person will understand that it is for a positive purpose and is therefore not lashon ha'ra.
 
 
Lashon HaRa and Specific Cases
 
Children, Shomer Shabbat Person, Groups
Even truthful lashon ha'ra, including rechilut, may not be said about a Jewish child or a shomer Shabbat person or group of people unless for a positive purpose that cannot be achieved any other way.

• A parent should not rebuke or criticize a child if it will embarrass the child in front of others.
• A child (whether young or adult) may not correct a parent who is saying lashon ha'ra, unless the parent would want to be reminded that the parent is saying lashon ha'ra. Even then, it must be done respectfully. 
• You may make statements about groups of people in general, even if negative, as long as the purpose is to protect other people from them. But what you say must be true.   

 
Lashon HaRa: Public Knowledge
You may mention information that is public knowledge. But your intent should not be to spread the word, but rather just to pass along interesting information.
Example
Saying, “Did you hear that the president of the synagogue just got convicted of...”
 
Lashon HaRa: Mass Media
You may read in the paper, see on TV, or hear on the radio an account of someone's bad behavior (since you cannot know whether it will affect you or be important for you to know until you read or hear the information, it may be OK; ask a rabbi). You may not accept it as being the complete truth, but you should be wary.
 
Lashon HaRa: Shomer Shabbat Public Figure
You may not tell or listen to lashon ha'ra about a public figure who is a shomer Shabbat Jew unless there is a purpose.
You may give your opinion about a shomer Shabbat politician as long as you state it as your opinion and as long as giving your opinion may help other people.
 
Lashon HaRa: Shomer Shabbat Organization
You may not say any of the three types of speaking ill about an organization, school, synagogue, etc., whose members or employees are shomer Shabbat--except for a positive purpose.
Examples
You may not say any of the three types of lashon ha'ra about a Jewish school's cost, bad teachers, etc., unless it may be relevant to future students (and even if it is relevant, you may still not say motzi shem ra).
You may not say, “I don't like that shul because there is lots of talking,” unless you think the person will appreciate knowing since he or she will not want to go to a shul with lots of talking.
 
Lashon HaRa: Asked for Opinion
If you are asked for your opinion, you may give it if it is relevant (has a useful purpose) to the person asking. Otherwise, no comment.
 
If you are asked your opinion about a Torah lecture or lecturer, you may give your opinion only AS your opinion, not as criticism.
 
Lashon HaRa: Told in Confidence
If you have been told something in confidence, even if you think it is best for the person who told you if you pass it along, you may still not re-tell anyone else. You may say, “I cannot speak about that” if you are asked. Consult a rabbi.
 
Lashon HaRa: Getting Back at Someone
If someone hurts you, you may get back at the person at the time of the action against you.  But afterward, it would be revenge and is forbidden.
Example
Someone tells you, “You are good for nothing.” You may say, “You are worse than I am,” if it makes you feel better.
 
Lashon HaRa: Bet Din Summons
If someone with whom you have a problem refuses a hazmana (summons) from a bet din, you may publicize a letter from the bet din saying the person refused the hazmana so that the recipient might agree to go to the bet din due to public embarrassment.
 
Lashon HaRa: Bet Din for Abuse
All matters between Jews should, ideally, initially go to bet din but only if the bet din is capable of resolving the problem. In cases of suspected child or spousal (or other) abuse, you may report it to the police if there is no bet din that is capable of dealing with the problem immediately: You are not required to wait while a bet din gets around to your case. The key is to expedite the case.
Note Some cities have special batei din for such matters.
Note Beware of governmental agencies that may take away children from their homes, even without evidence.
 
Listening to and Believing Lashon HaRa
Listening to and believing any category of lashon ha'ra is also forbidden. If you do hear something bad about someone else, do not believe that it is definitely true--but you may believe that it might be true. When you hear lashon ha'ra:

• You can try to change the subject, since pointing out that lashon ha'ra is being said may not stop it from being said.
• If you see a shomer Shabbat Jew doing something that seems to be forbidden, you should judge him/her favorably and assume that there is a good interpretation to what is being done.

Example
Situation
You see someone who is not shomer mitzvot get in a car on Shabbat.
What To Do
Make the logical assumption that he/she is going to drive (and not for a halachically permissible purpose).
Situation
You see a shomer Shabbat person get in a car on Shabbat.
What To Do
Assume there is a good, halachic reason for it. However, you may not ignore reality or make implausible or unlikely excuses for bad behavior.

Say the fore-blessing borei minei mezonot on non-bread foods if:

• Grain
  The Five Grains (wheat, rye, oats, barley, or spelt) make up at least 20\% of the food's flour volume, AND
• Cooking Method
  Food is cooked or baked, AND
• Meal or Snack
  You intend to eat the food as a snack and not a meal.
  Note If you intend to eat a full meal that includes mezonot of a cake-like or bread-like texture, say ha'motzi.
  For basing the fore-blessing on the main or preferential ingredient in a food mixture and/or saying two fore-blessings, see Fore-Blessings (Bracha Rishona): Food Mixtures: Main Ingredient  and Introduction to Food Fore-Blessings (Bracha Rishona): The Five Grains.

You must say the blessing which was designed to be said on each type of food. B'diavad, a lower level blessing will still cover the food.
From lowest to highest level, here are the food fore-blessings:

• She'hakol,
• Borei pri ha'adama,
• Borei pri ha'eitz (on common fruits),
• Borei pri ha'eitz (on the Five Special Fruits)

You may leave the sukka due to extreme cold or heat, rain, or bees. You should not stay in a sukka if it is raining or very cold or will otherwise make people suffer.
If it is raining on the first night of Sukkot and the rain is sporadic, wait until midnight before saying kiddush indoors.
If it is raining on the first night of Sukkot and the forecast predicts rain all evening, you do not need to wait to see if the rain will stop before saying kiddush. Instead:

• Say kiddush in the sukka (without saying leisheiv ba'sukka), even in the rain.
• Wash hands and say ha'motzi.
• Eat at least 1.3 fl. oz. (39 ml, or 1/6 cup) of bread in the sukka.
• Go inside the house and finish your meal inside. 

When washing your hands before eating bread, the ideal procedure is to wash, say the blessing al netilat yadayim, and then dry your hands (since the drying is part of the washing procedure). Many people have the custom of pouring water onto each hand twice but only before eating bread.

The fore-blessing (bracha rishona) must be said where you eat.  However, sometimes you may begin eating in one domain and continue eating in another domain. A domain may be any physically limited area (car, house, restaurant, office building) or the outdoors (highway, park, etc.). Once you left the first place, you are considered to have had an interruption of thought (hesech da'at) and are no longer eating that original snack or meal. 
Whether you say a new fore-blessing depends on your intention when you said the fore-blessing:

• Do not say a new fore-blessing if you had intended to go to the second place, as long as the food at the second place is in the same food categories as what you already blessed on at the first place.
• Say a new fore-blessing if you had not intended to continue eating in the second domain, even if you had planned to return to that first place and continue eating.
  Exception You do not need to make a new fore-blessing if:

  • You return to the first place and even one person who was eating with you is still there, OR
  • You had eaten bread or mezonot and then left but had not said the after-blessings of birkat ha'mazon or al ha'michya, even if no one is left from before.
    Reason Since you are required to say birkat ha'mazon or al ha'michya, you are still considered to be continuing your meal.

    Note As long as you are under the same roof, do not say new blessings on food at the new place (such as when switching seats or even rooms in a restaurant).

    Exception Even if you washed your hands and said ha'motzi at the first place, say a new blessing on food that would have required a new blessing at the first place, such as new wine or any dessert other than mezonot.