For your children you must be explicative

About expletives. (Use the indicative).

When your canny preteens

Ask what “what the f-?” means

Say, “it literally means 'what the fricative!'”

Based on the suggestion: “voiceless fricative”

Voiceless fricatives are those consonants that consist of unvoiced air being expelled, like “f” “th” (as in “think”) “s” “sh” and “h.” Voiced fricatives are “v” “th” (as in “the”) “z” and “zh.”

The indicative tense is for stating facts (as compared with the subjunctive tense, which is used for uncertainties, and the imperative tense, which is used for commands).