The TeXbook describes all your options in detail.
?’ that appears after the context display means that TeX wants advice about what to do next. If you've never seen an error message before, or if you've forgotten what sort of response is expected, you can type ‘
?’ now (go ahead and try it!); TeX will respond as follows:
Type <return> to proceed, S to scroll future error messages,
R to run without stopping, Q to run quietly,
I to insert something, E to edit your file,
1 or ... or 9 to ignore the next 1 to 9 tokens of input,
H for help, X to quit.
This is your menu of options. You may choose to continue in various ways:
Simply type〈return〉. TeX will resume its processing, after attempting to recover from the error as best it can.
S’. TeX will proceed without pausing for instructions if further errors arise. Subsequent error messages will flash by on your terminal, possibly faster than you can read them, and they will appear in your log file where you can scrutinize them at your leisure. Thus, ‘
S’ is sort of like typing 〈return〉 to every message.
Type ‘R’. This is like ‘S’ but even stronger, since it tells TeX not to stop for any reason, not even if a file name can’t be found.
Q’. This is like ‘
R’ but even more so, since it tells TeX not only to proceed without stopping but also to suppress all further output to your terminal. It is a fast, but somewhat reckless, way to proceed (intended for running TeX with no operator in attendance).
I’, followed by some text that you want to insert. TeX will read this line of text before encountering what it would ordinarily see next. Lines inserted in this way are not assumed to end with a blank space.
Type a small number (less than 100). TeX will delete this many characters and control sequences from whatever it is about to read next, and it will pause again to give you another chance to look things over.
H’. This is what you should do now and whenever you are faced with an error message that you haven't seen for a while. TeX has two messages built in for each perceived error: a formal one and an informal one. The formal message is printed first (e.g., ‘
! Undefined control sequence.’ ); the informal one is printed if you request more help by typing ‘
H’, and it also appears in your log file if you are scrolling error messages. The informal message tries to complement the formal one by explaining what TeX thinks the trouble is, and often by suggesting a strategy for recouping your losses.
X’. This stands for “exit.” It causes TeX to stop working on your job, after putting the finishing touches on your log file and on any pages that have already been output to your
dvi file. The current (incomplete) page will not be output.
E’. This is like ‘
X’, but it also prepares the computer to edit the file that TeX is currently reading, at the current position, so that you can conveniently make a change before trying again.
After you type ‘
H’ (or ‘
h’, which also works), you'll get a message that tries to explain that the control sequence just read by TeX (i.e.,
\vship) has never been assigned a meaning, and that you should either insert the correct control sequence or you should go on as if the offending one had not appeared.