Learn how to say Certainly correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word certain:
1able to be firmly relied on to happen or be the case:
it’s certain that more changes are in the offing
she looks certain to win an Oscar
having or showing complete conviction about something:
are you absolutely certain about this?
2 [attributive] specific but not explicitly named or stated:
he raised certain personal problems with me
the exercise was causing him a certain amount of pain
used when mentioning the name of someone not known to the reader or hearer:
a certain General Percy captured the town
some but not all:
certain of his works have been edited
without any doubt:
I don’t know for certain
[with clause] take action to ensure that something happens:
make certain Lewis knows all the facts
I made certain that our paths would never cross again
establish whether something is definitely the case:
he probably knew her, but it didn’t do any harm to make certain
Middle English: from Old French, based on Latin certus ‘settled, sure’
Remember that certain ends with -ain.