on certain occasions

"On certain occasions they haven't been able to keep up with the questions I've asked and maybe that's why it ended."

He told the BBC that in America he employs security on certain occasions and that the UK still offers him state protection "like the good old days".

Junnila, who survived a no-confidence vote at parliament earlier this month, also reportedly has made improper references to Adolf Hitler and Nazi Germany on certain occasions.

Servais mentioned the idea of putting Raleigh and Murphy in the lineup at once on certain occasions.

McCarthy’s office didn’t necessarily mind how things looked during the vote and is open to greater access on certain occasions.