German Phrase
Ich bin mir da nicht sicher.
Meaning
The speaker expresses uncertainty about a specific point that has just been mentioned or is understood from context. It literally means “I am not sure about that,” but it can also be rendered as “I’m not certain about that” in English.
When to use
Use this phrase when you want to politely indicate doubt or lack of confidence about something that has been said, a plan, or a piece of information. It works well in both formal and informal conversations.
✦Grammar Breakdown
Ichbinmirdanichtsicher
Reflexive pronoun with "sicher sein"
"sicher sein" takes a dative reflexive pronoun (mir, dir, ihm…) to indicate who holds the certainty.
"da" as a deictic adverb
"da" points to a previously mentioned idea or situation; it can be replaced by "darüber" for more formality.
Negation placement
In German, "nicht" precedes the adjective or adverb it negates—in this case, "sicher".
Verb position in main clause
German main clauses follow the V2 rule: the finite verb "bin" occupies the second position.
🗨In Conversation
Wir sollten das Meeting auf Freitag verschieben.
We should move the meeting to Friday.
Ich bin mir da nicht sicher. Vielleicht ist Montag besser?
I’m not sure about that. Maybe Monday is better?
✕Common Mistakes
Ich bin nicht sicher da.
The adverb "da" should come before "nicht" and the reflexive pronoun "mir" is required.
Ich bin mir nicht sicher das.
Use "da" or "darüber" instead of "das" after "nicht sicher".
↔Alternatives
Da bin ich mir nicht sicher.
I’m not sure about that.
Ich bin mir darüber nicht sicher.
I’m not certain about it.
Das ist mir nicht ganz klar.
That’s not entirely clear to me.
Cultural Tip
In German, using the dative reflexive "mir" with "sicher sein" is the standard way to express personal certainty. Avoid the English‑style "Ich bin nicht sicher" without the dative, as it sounds incomplete. In more formal settings you can replace "da" with "darüber" for a slightly more precise reference.