The more I think about these three, the more I get confused about when to use which. kapag: I feel like this means "when" as in "whenever" or "while". noon: I know this has to do with the past such as "ago" or "at that time". nang: This is the one I'm not really sure about. I feel like it has overlap with noon. Here are some example sentences I just made up: Masaya ako kapag nakikita kita --> I am happy whenever I see you (?) Masaya ako noon kapag nakikita kita --> I used to be happy whenever I saw you (?) Masaya ako nang nakita kita --> I was happy when I saw you (?) [the act of seeing you made me happy, I became happy when I saw you] Masaya ako noong nakita kita --> I was happy at the time I saw you (?) [I was already happy when I saw you?] As a side note, I was talking to my mom a few months ago I think I said Tatawagan kita nang matatanggap ko ang package mo. She corrected me with kung: Tatawagan kita kung matatanggap ko ang package mo. I might not remember that sentence correctly, but the question I'm trying to bring up is the use of kung for "when". Does this mean kung would be used in sentences like: Turn off the faucet when you brush your teeth. Wash your hands when you eat.