to make sure
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to make sure
To ensure or check that something is in a certain state or corresponds to the truth. You gain certainty about something.
Bevor sie das Haus verließ, vergewisserte sie sich, dass alle Lichter ausgeschaltet waren.
Before she left the house, she made sure that all the lights were turned off.
The verb 'vergewissern' (to make sure) contains the word 'gewiss', which means 'certain' or 'sure'. 'Sich vergewissern' (to make sure) therefore literally means to obtain certainty for oneself about something.
Ich wollte mich nur kurz vergewissern, dass es dir gut geht.
I just wanted to quickly make sure that you're doing well.
This verb is always used reflexively with 'sich'. You cannot 'vergewissern' another person; you can only do it for 'sich selbst' (oneself).
Er vergewisserte sich, dass er seinen Schlüssel eingesteckt hatte.
He made sure that he had put his key in his pocket.
Most often, 'sich vergewissern' (to make sure) is followed by a subordinate clause with 'dass' (that) or 'ob' (whether/if), which explains what one is gaining certainty about. Less common and more formal is the use with a genitive object.
Kannst du dich bitte vergewissern, ob die Post schon da ist?
Can you please make sure whether the mail has arrived yet?
to confirm
'bestätigen' and 'sich vergewissern' both fit situations where you need certainty about something. 'bestätigen' means that you assure something is correct, often to another person. 'sich vergewissern' means that you yourself check whether something is really true or okay. The risk of confusion lies in the fact that both have to do with certainty. But the direction is different: someone who 'bestätigt' gives certainty; someone who 'sich vergewissert' gets certainty for themselves.
Vor dem Aussteigen vergewissert sich die Klasse, dass alle Taschen im Bus sind.
Before getting off, the class makes sure that all the bags are on the bus.
Sie bestätigt dem Arzt den Termin für nächste Woche.
She confirms the appointment with the doctor for next week.