problem of grammer

[Claradai]

There are eight speciess of the geuns Canis,?.
1.all are wild,excepting only one
2.of all only one is wild
3.all but one of which is wild
4. all except only one of which are wild

Answer is 4 , but I do not know 〝all except 〞what it means.

〝only one of which are wild 〞. why not use〝 is 〞,I see the〝 one〞.

[philo2009]

'All except' is a slightly unnatural way of saying 'all but'. The subject of the relative clause is 'all', here having plural reference (back to 'species', also plural here), and it therefore governs the verb in the plural: thus 'are', not 'is'.

'One', on the other hand, is simply the object of the preposition 'but/except'. ('But' is more typically a conjunction, but functions prepositionally in this kind of construction).