grammar - Why is this sentence grammatically incorrect?

On a separate question about Japanese pitch, one of the examples I left was:

'甘美（うまみ）の花は赤を見える' (Your flower looks red [talking to Umami]).

One of the commenters claimed that it was grammatically incorrect and Chocolate edited it to correct the mistake:

'甘美（うまみ）の花は赤く見える'

I understand that certain verbs have different particles for different contexts etc.

What is the purpose of く replacing を? Is く better, or is を also exceptable? If so which is better and why? I apologise for the multitude of questions.

Answer

In Japanese language it is possible to use adjectives and their inflections in order to have more structured and articulated sentences. In the specific case you want to express a concept recalling the one when a certain object looks like something else. When this happens, adjectives are involved.

The correct way

The pattern for such a concept to be expressed is the following:

(Noun)は|が(い->drop)く見える

(Noun)は|が(な->drop)に見える

Remember always that when an adjective is to be turned into an adverb you need to drop the い and put く (in case of い-adjectives), or drop な and put に in case of な-adjectives. The case here is similar, because you need to turn the adjective into an adverb and then apply 見える.

The not (quite) correct way

You mentioned Chocolate. That user is a native Japanese speaker so please listen to what she says because it is correct. In fact the sentence you mentioned in the very first lines of your question is the following:

甘美{うまみ}の花は赤を見える

This sentence is not correct at all in my opinion. It all revolves around the verb 見える. This verb can be interpreted in two ways:

1. 見える as a "standalone" 一段{いちだん} verb.


2. 見える as (one of) the (two possible) potential form(s) of 一段{いちだん} verb 見る{みる} (to see). It might sound like a 五段 verb but it is an 一段 instead, be careful.

The first verb acts the way I told you. Here you might tell me that in your sentence there is no adjective (as you use 赤 and not the corresponding adjective 赤い), well in that case it is treated as a な-adjective and you will use the に as follows:

甘美{うまみ}の花は赤に見える

The pattern is the following (you can add this to the other two patterns I mentioned before):

(Noun)は|がに見える

The second verb is used in a potential context when you want to say that you can see something. Unfortunately there is another potential form for the verb 見る but I will not detail it too much. Just now I am showing you how your sentence is supposed to be changed in order to use such a verb (and how the meaning changes as well):

甘美{うまみ}の花が見える ==> I can see Umami's flower

Conclusions

This is just to point that a verb like 見える can be used in two possible contexts, but not one of them includes the possibility to use particle を! Hope this helps you.