ABSTRACT
There is an important distinction of sense between the two. In the first example, whether or not Ron is here is an open question - he may or may not be, but if he is, the speaker will tell him whatever it is he has to tell him. But in the second example, it is clear that Ron is not here at all, and that this is a hypothetical situation-'I would tell him', after all, means in effect that I'm not going to (I can't, because Ron's not here). The first type of condition above is called an open condition, because we simply don't know one way or the other; while the second is called a closed condition. You need to be able to identify them, and the best way is to look at the half of the English sentence that doesn't contain the 'if': if this non-'if' clause contains a 'will', then we have an open condition; if it contains a 'would' (or 'could', 'should' or 'might'), then we have a closed condition. This distinction is particularly important in Welsh, because there are different words for 'if' in open and closed conditions.
