Should is from shall. It's English, not French.duszek wrote:"should" can be used in conditional sentences
In case you arrive late please do this and that. =
Should you arrive late please do this and that.
Should is subjuctive mood of shall.
Perhaps the French grammar could provide some further explanation.
Do we have any French grammarians here ?
The Norman conquest, you know.
I love to explore linguistic enigmas, don´t you ?
Should indicates what ought to be in terms of obligation or probability.