Lef-tenant is a British rank, lieu-tenant is an American rank. Each is correct when used in their own context, but not otherwise. It'd be wrong to call a US General a "Field Marshall", so it'd be wrong to call a British Lieutenant a "loo-tenant".

As for "recognise" and "recognize", both are correct, they're interchangeable - there isn't even a "national difference" between the two; one isn't exclusively American or British.

"Aluminium" is far more consistent than "aluminum", since few or no other elements have "-um" endings, although many end with "-ium".

"Sulfur" is more practical and straightforward than "sulphur", but only because chemistry is becoming an 'international language' and 'ph=f' would be rather confusing for those who aren't native speakers of English.