(k+1)th, (k+1)st, k-th+1, or k+1? (Inspired by a question already at english.SE) 
This is more of a terminological question than a purely mathematical one, but can possibly be justified mathematically or simply by just what common practice it. The question is:
When pronouncing ordinals that involve variables, how does one deal with 'one', is it pronounced 'one-th' or 'first'?
For example, how do you pronounce the ordinal corresponding to $k+1$?
There is no such term in mathematics 'infinityeth' (one uses $\omega$, with no affix), but if there were, the successor would be pronounced 'infinity plus oneth'. Which is also 'not a word'.
So then how does one pronounce '$\omega + 1$' which is an ordinal? I think it is simply 'omega plus one' (no suffix, and not 'omega plus oneth' nor 'omega plus first'.
So how ist pronounced, the ordinal corresponding to $k+1$?


*

*'kay plus oneth'

*'kay plus first'

*'kay-th plus one'

*'kay plus one'


or something else?

From the Handbook of Writing for the Mathematical Sciences section 5.5 p. 63:

Here are examples of how to describe the position of a term in a sequence relative to a variable k:
kth, (k+1)st, (k+2)nd, (k+3)rd, (k+4)th, …
  (zeroth, first, second, third, fourth, …)
Generally, to describe the term in position k±i for a constant i, you append to (k±i) the ending of the ordinal number for position i (th, st, or nd), which can be found in a dictionary or book of grammar."

So the formal answer is that it should be:

(k+1)st

