‘Ce’ and ‘Se’ are homophones. They sound exactly the same, but their meanings and spellings are completely different:
-‘Ce’ is a demonstrative pronoun. The translation for ‘ce’ is generally “that”, “this” or “it” in English.
-'Se' is a reflexive pronoun. The translation for ‘se’ is “oneself/himself/herself” in English.
So how do I know whether to use Ce or Se?
The rule is simple: there are two possible cases.
1-If the pronoun you are trying to spell is not in front of a verb (so if it is in front of a noun, an adjective, etc.), then you must use ‘ce’.
Example in front of a noun:
> ‘Ce/se chien est très vieux’ (=That dog is very old)
> here, the pronoun you are trying to spell is in front of a noun (chien=dog)
> So the correct spelling would be ‘Ce chien est très vieux’.
Example in front of an adjective:
> ‘J’ai acheté ce/se beau pull’ (=I bought this pretty sweater)
> here the pronoun you are trying to spell is in front of an adjective (beau= pretty)
> So the correct spelling would be ‘J’ai acheté ce beau pull’.
2)If the pronoun you are trying to spell is in front of a verb, then you need to replace the pronoun with the phrase ‘cela est’ (= “it is”) and check if your sentence still makes sense. If it does, then you can use ‘ce’. If it doesn’t make sense, then you must use “se”.
Example where ‘cela est’ makes sense:
> ‘Ce/se n’est pas facile’ (=It’s not easy)
> here the pronoun is in front of a verb (n’est= is not). To know which spelling to use, replace the pronoun with the phrase “cela n’est” (no tricks here! ‘cela n’est’ is just the negative version of ‘cela est’ and means= it is not). Check if your sentence still makes sense.
> ‘Cela n’est pas facile’ (=it is not easy)
> The sentence makes sense. Therefore you can use ‘ce’ and the correct spelling would be ‘Ce n’est pas facile’
Example where ‘cela est’ does not make sense:
> ‘Juliette ce/se lave’ (=Juliette is washing (herself))
> here, the pronoun is in front of a verb (laver= to wash). To know which one to use, replace the pronoun with the phrase “cela est”. Check if your sentence still makes sense.
> ‘Juliette cela est lave’ (=Juliette it is washing)
> The sentence makes no sense. Therefore, you must use ‘se’ and the correct spelling would be ‘Juliette se lave’.
Voilà, now you know when to use 'ce' and 'se'! Please do not hesitate to get in touch with me if you have any questions!