Hi

I've recently learnt that there is the structure 太(Adjective)了 to emphasise adjectives. Now I wonder if in the negative form we also have to end the structure with 了.

This laptop is not very expensive. Which is correct?
a) 这部笔记本电脑 不太贵。
b) 这部笔记本电脑 不太贵了。

Thanks in advance,
G.

 

You can't use 不太 with 了.
太(Adjective)了 is a kind of exclamation. “not very” doesn't sound like an exclamation. Instead, I would say “太便宜了”.

“太adj了” is normally used positives forms, but sometimes you will see “太不adj了”:
太不走运了
太不靠谱了
太不像话了
……

 

Since 了 following 太 as a kind of exclamation, it can follow negative combinations also, as long as the speakers feels the exclamation is warranted in the context. In other cases, such as in the examples given by YangMuyue above, 不走运, 不靠谱, 不像话 are all treated as single descriptive words, so they do conform to the pattern: "太+ Descriptive Word +了"

 

Interesting. Just to clarify, does this pair of sentences have the same meaning?

这部笔记本电脑 太不便宜了。
这部笔记本电脑 太贵了。

 

Since there is this word "(太)贵", no one would use "(太)不便宜", unless as a joke (or s/he is a learner of Chinese )

 

My previous teacher of Chinese told us that 不 + (Opposite of an adjective) is not an uncommon way to "reword" an adjective when emphasising it, is that not so? Thanks

 

I don't say 太不便宜了。

I don't think so. It seems to me that some adjectives tend to be used with 不. e.g. 不错, 不对, 不菲 etc. Saying “对”, “错” “菲” often sounds unnatural. It's not a simple rewording.
For most adjective, I think there is a difference in degrees, e.g. “便宜” < “不贵” < “不便宜” < “贵”.

 

Of course you can use 不太with了, if the laptop used to be expensive, but now it's cheaper, you can say 这部笔记本电脑现在已经不太贵了。

 

In this case 了 signifies a "present perfect tense", i.e. indicates the change of status, or the finishing of an action.
In the original sentence "This laptop is not very expensive." 了 shouldn't be added.