Someone British will have to address childminder (that is not used in the US). However, babysitter and nanny (at least in the US) are basically interchangeable now. The only slight difference is a babysitter is someone who watches the kids for the parents less often while a nanny usually is hired with a specific schedule. Nanny also implies the person is trained while a babysitter could be anyone who is getting paid to watch kids (not someone necessarily trained to do it). "The nanny comes every Tuesday and Thursday." "We have a babysitter for Saturday." Hope that helps!

Babysitter is the only common word here. "I wish my child had a babysitter." "I work as a nanny." "She works as a childminder".

In the UK here's how it usually works... Childminder is a formal term that people would rarely use in casual conversation. It's often used in documents. It specifically means anyone who supervises children - especially people whose job it is to specifically supervise them. Babysitter is a common word, which is sometimes used for elder children like teenagers and even adults (just as the word kidnap can apply to adults and even animals - not only kids), but the use of the word "baby" makes it more common to use in relation to babies and toddlers (young children who can not yet speak). Babysit contains the word "sit" which relates to how this word is commonly applied to friends who sit down in your house and stay with your children for an hour or two while you go out. Thus the word babysitter rarely applies to professional childminders who exclusively use their own premises and require formal notice in advance and specific times adhered to, etc. Nanny is a slightly more vague term. It usually refers specifically to simple supervision of children, but is often also assumed to include additional duties such as those included in the role of an Au Pair. In the UK many people even use the word Nanny in place of "grandmother" (colloquially "Nanny and Pappy" or "Nan and Pap" means "Grandmother and Grandfather" to many people, in common casual slang). So if you're referring directly to the supervision of children and want a specific yet cold, formal word, use the term Childminder. If you're speaking specifically about infants being cared for by a friend in a casual manner, say Babysitter. And if you're speaking of a grandmother type of figure, who has a generally warm and caring demeanour and may wash some clothes and tidy your house a little more than is strictly necessary, you might say Nanny. If neither of these particularly apply, it's a complex judgement call that many native English speakers will automatically make without even thinking consciously about it!