I'd say I have met a lot of native speakers that, while obviously native, have poor vocabulary skills (and also make some grammar mistakes - but not the ones the ESL students usually make)
It's not surprising to have people that have trouble with words like rotund, pulmonary, saturnine, among others. (Or the usual mistakes like "should of", "it's" when they mean "its", etc)
I'd say I have met a lot of native speakers that, while obviously native, have poor vocabulary skills (and also make some grammar mistakes - but not the ones the ESL students usually make)
It's not surprising to have people that have trouble with words like rotund, pulmonary, saturnine, among others. (Or the usual mistakes like "should of", "it's" when they mean "its", etc)