I'm confused about when "se" should be used. I thought it would always go before a like here:
Ella se mejora a su coche
but I see here that it is not being used.
Él observa a su hija
My question is, when is
se used before the verb?
Emilio's links are correct.
I will focus on the wide use of
In your first example you can drop the reflexive pronoun and everybody will understand you, it is just extra information.
In the second example you mention:
You are asking about Él se observa a su hija
Él se observa a su hija --> He watches by himself to her daughter / He watches her daughter (by) himself.
I am not English but it sounds a bit strange to add
I think I won't be wrong if I ask you to put in these sentences the pronoun themselves.
Las enfermeras están vigilando a los chicos --> The nurses are watching the children.
For other uses you can use this website http://spanish.about.com/
I am learning English so this answer can contain errors when it comes about translations and different uses of pronouns in English examples
Reflexive verbs are, in my opinion, the easiest
At the bottom of the list above are some other reflexives that do not express emotion, but rather, consumption of some kind, whether it be yourself or something else, a consumption of ... all of it... as the quote says.
I would call this the opposite of a Reflexive verb. These are personal verbs that involve another subject, as the definition suggests.
In the Spanish language, for some reason, they do not accept the blame. You don't forget your wallet, your wallet forgets you. It's strange, but it's true.
You will often hear this usage when you are asked how to say something.
Using English as an example you can see the trend used in this form of SE.
In English, we use "they" or "you" a lot to explain instructions, or advertisements, or, mainly, just to generalize... in some cases, "we"... as in
Other English examples -- in spanish.
This impersonal "se" is a bit tricky to get used to. I still use it incorrectly to this day, even after 15+ years of practice and education.
Taken from my Advanced Spanish Manual, written by Veronica Martinez of ITESM Querétaro.
Just wanted to add some additional examples to maybe help clear your confusion of when to use se or when not to use, coming from a native speaker.
As others have already mentioned, the main use of "se" is reflexive. Compare/contrast the meaning of the following examples:
A more complicated example could be something that is inherently reflexive, like
but I would argue that the fact these two statements express is the same, perhaps with only a slight change in emphasis. I hope these examples helped clear some of your confusion up.