"我当然没有告诉他。"

Translation: Of course I did not tell him.

[bould1]

I'd like to suggest that no capital letters be used in the list of English word choices except where grammatically necessary so that the student must decide which word opens the sentence. The app always capitalizes the first word in the sentence, in effect giving the answer.

[Dejo]

If you don't capitalize one word then you will end up with more syntax variation and complaints about why your sentence wasn't accepted. In this particular sentence my first impulse was to say "I didn't tell him, of course" and I'm sure that would have been rejected.

[Peter519121]

Don't look at the options before you figure out the answer.

[EricLuo4]

当然 can also be "obviously"

[hippietrail]

And "definitely".

[KX3.]

A more direct translation for "obviously" is 明显的/地, and for "definitely", 肯定/一定/铁定.

[Krstna12]

How do you know what tense to use? Why is it in the past tense here?

[DereckStJohn]

Chinese doesn't have a past tense. The use of (没)有 indicates "(not) experienced" which in English can be translated as "didn't" or "haven't" depending on the context.

[ebro3]

Why is 'Of course I won't tell him' not acceptable?

[Patrick_Dark]

"I did not tell him, of course." should also be accepted.

[deactivated user]

... just how treacherous this Chinese tree was going to be!

[deactivateR]

I would also like to know what the distinction would be for "of course I won't tell him"

[Boondock4]

Can't of be on the end. Like "I did not tell him of course."

[griscarl]

As long as you remember to put a comma after "him". :)
"I did not tell him, of course."