"Ti dicevo ieri che non erano buoni."

Translation: I was telling you yesterday that they were not good.

[luke.floyd24]

I was telling you yesterday that they were not well.

This was not accepted..?

[mrule]

It may be enforcing the (adjective/adverb) (good/well) (buono/bene) distinction. In this case, I think duolingo is wrong and you are correct -- since "well" can be both an adverb and adjective in English. But, the server probably doesn't really understand this yet.

[jzzybme]

buono is always good. Bene can be good or well, but is mostly used for well.
Mangio buono = I eat good (bad grammar in english)
Mangio bene = I eat well.

[madmcmurphy]

And why is "I told you yesterday that they were not kind" incorrect? Kind is an acceptable translation of the word "buono", it is even shown in the hints here

[Emrani]

I suspect that "I told you yesterday" would be more correctly translated with the perfect tense - "Ti ho detto ieri" - but perhaps a native Italian speaker could confirm this?

[Matteo_Ce]

Mmm we don't really use the adjective "buono" to say kind.
We use "gentile" or " cortese". "Buono" used for a person means a very calm and silent one.

[jarrettsmith]

Yesterday I told you that they weren't good? Does anyone know why that isn't
accepted

[Rompip]

I also tried this. Does it mean something slightly different? As in, 'yesterday I told you ...... but today i've changed my mind' versus 'I told you yesterday ...... so today you should have known'? Just guessing.

[coledanielj]

Isn't the tense incorrect in your sentence? Told is one time while was telling is continuous

[TheFinkie]

I'm finding this tense quite difficult. Is it or is it not past continuous? Because I thought there was a different tense used in Italian for past continuous.

[UlrikeKar]

I was telling you yesterday that they were not well.

This is the correct english translation. Die grammatikalische Übersetzung Italienisch - Englisch ist oft einfach falsch. Leider, denn das ist sehr schlecht für anderssprachige Schüler, die Englisch ebenso als Fremdsprache lernen.

[coledanielj]

'bene/ben' is well, 'buono' is good.

The rule of thumb is that good is an adjective (here used as a predicate adjective) and well is an adverb. Good modifies a noun; something can be or seem good. Well modifies a verb; an action can be done well (sings well, nothing ends well). However, when you're talking about health, well can be used as an adjective.