If you have serious evidence to support your suspicion such as bruises, suspicious injuries, sudden dramatic changes in temperament, strange behaviours, or other signs of abuse, you should contact the authorities in your area. Physical abuse is a serious issue and can suddenly escalate in severity, putting the child at risk for serious harm, while other forms of abuse are often less recognizable but can be just as damaging to a child's emotional development. Now, with that in mind, many signs of abuse can be caused by other issues such as accidents, family conflict, trouble at school, or even illness, making it difficult to know what to do.
Children get hurt, they get bruised and scraped, and some are truly more clumsy (or more adventurous) than others but if you suspect physical abuse, ask the child about their injuries. If their answer strikes you as suspicious, if the child is evasive, awkward, or their explanation doesn't match the injury, you should be concerned. Sometimes it's just a matter of a gut reaction, that their answer just feels "wrong" or "off" but when a child's welfare is on the line, it's important not to brush off these concerns or step back just because you don't know for certain.
Often, abuse is justified by parents as disciplinary action but laws about what type of physical discipline is acceptable differ depending on where you live. A quick call to your local child protection agency or the police will tell you if what the child has described to you is distinctly illegal or not. That being said, "legal" spankings can be deemed illegal abuse depending on the severity, the frequency and other factors, so just because it might technically fall under that heading in your province or state doesn't mean it's something you don't need to report. Laws allowing some forms of physical discipline can make abuse hard to recognize, sometimes even for the abusive parent, but if you are concerned, inform the appropriate authorities who are trained to assess these matters. If it is a case of discipline taken too far, often parents won't lose custody of the children but will be required to take parenting classes or demonstrate that they understand their mistake and are able to change how they deal with their child, leading to a positive outcome for everyone involved.
Neglect or emotional abuse
It is often harder to recognize neglectful or emotional abuse. Undo criticism, threats, lack of care, disregard and disinterest, lack of supervision, or other inappropriate parent-child interaction are some of the hallmarks of this type of abuse. If you suspect neglect or emotional abuse, evidence can be harder to spot but you should write down the instances when you notice something suspicious or alarming as it is often the pattern of behaviours or events which reveals what is really going on. Specific things you can look for in the child include untreated medical conditions, difficulty focusing at school, extreme behaviours, begging or stealing money or food, and/or a lack of attachment to the parents.
Sexual abuse is a complicated matter. Broaching the subject with a child can be very difficult and, if not handled appropriately, can actually cause additional trauma and/or put you at risk for suspicion or accusations of inappropriate behaviour. If you notice signs of sexual abuse in one your child's friends, keeping track of your observations in writing can help you see the bigger picture. If you do have serious concerns, it's best to contact authorities and let them handle the investigation. If the child mentions abuse to you, even in an off handed way, he or she is probably looking for help but is embarrassed and/or afraid. Pay close attention, let them talk as much as they need to, and avoid asking any leading questions. If possible, it's a good idea to have another adult present, but this may make the child uncomfortable or less willing to talk. Bringing this type of thing up takes a lot of courage and shows that the child trusts you and if you put it off or try to delay it, you might miss the opportunity or make them feel like you don't want to hear about it. Taking notes while the child is talking might make them uncomfortable but as soon as you can you should try to write down specific details, such as dates, frequency of abuse, and specific acts, using the child's own words as much as possible. Tracking what you said, what questions you asked, will also help authorities accurate assess the situation.
What you can do
With any kind of abuse, keeping records and tracking your suspicions is important. By noting the date and the child's exact words or the specific concern (i.e. had no lunch at school, suspicious bruises, was left home alone for an inappropriate amount of time given the child's age etc..) will help you keep a realistic view on what is happening as well as giving you accurate information to pass on should you deem the matter worth reporting.
Often if a child is being abused, local child protection agencies will have already had some reports about the family from other sources but additional evidence or information is always helpful, and often needed. If the family has not had any previous reports, there is all the more reason to make your concerns known so that those with experience can look into the matter. If there is no abuse in the home, an investigation won't find anything amiss and that will be the end of the matter.
If you want to ask the child about the suspected abuse, or if they broach the subject with you, it is important that you let them talk, keep your questions open-ended and maintain an non-judgemental attitude. Shocked, disgusted or severe reactions from you might be interpreted as being directed at them so while empathy and expressing concern for the child is important, you must also do you best to keep your emotional reactions in check. The best thing you can do in these situations is let the child know he or she has been heard, make sure they've said all they need to say, reassure them that your opinion about them hasn't changed, that you don't blame them, and that whatever happened was not their fault.
Open-ended questions such as "ouch, that looks painful, how did you get that bruise/scar/mark?" or "you seem upset, is everything okay?" are appropriate ways to start a conversation about your concerns. If the child starts the conversation you can encourage them with statements like "I know this is hard to talk about but you're doing really well" or "wow, that sounds really awful, can you tell me more about what happened?". Reflecting their emotions and acknowledging how they feel by saying "I know you're scared", "it's okay to be scared" or "you seem embarrassed about this but it's okay, you have nothing to be embarrassed about" can also help them feel validated and supported.
The bottom line is that if you have serious concerns seek help from those who have more experience with these matters such as the police or local child protection authorities. A child's welfare is at state and if no one speaks up, that child will never get the help he or she may desperately need.