Breakdown of S'il te plaît, sois ponctuel ce soir.
être
to be
ce soir
tonight
s'il te plaît
please (informal)
ponctuel
punctual
Questions & Answers about S'il te plaît, sois ponctuel ce soir.
Why use sois instead of es if it means "be"?
Because this is a command (the imperative form). For most verbs, the command form looks just like the present tense, but être is irregular. To tell one person (informally) to "be" something, you must use sois.
How do we know this is addressed to one person informally?
The sentence uses s'il te plaît (using the informal pronoun te) instead of s'il vous plaît. It also uses sois, which is the tu (informal singular) command form. They both match up!
Would this sentence change if you were speaking to a woman?
Yes! Adjectives must agree with the person they describe. ponctuel is the masculine form. If you are talking to a woman, you must make it feminine by doubling the L and adding an E: sois ponctuelle.
Why does it say ce soir for "tonight" instead of using the word for "night"?