Omitting ようだ at the end of a sentence


> 父はデジタルカメラの講習を受けに行ったが、あまりの難しさにびっくりしたようだ。

So this sentence is saying, "my dad went to take a short course on digital
cameras, but it was difficult to the point of surprising him." Could you say

> 父はデジタルカメラの講習を受けに行ったが、あまりの難しさにびっくりした。

instead or would omitting the ようだ make the sentence incorrect. What is the
point of the ようだ at the end of the sentence?




The sentence is complete and _grammatically correct_ without ようだ. (Please also
see Tsuyoshi Ito's answer.)

…ようだ adds "It seems that ...".

In this case,

> 父はデジタルカメラの講習を受けに行ったが、あまりの難しさにびっくりしたようだ。  
>  My dad went to take a short course on digital cameras, but it seems that he
> was surprised at just how difficult it was.




> 父はデジタルカメラの講習を受けに行ったが、あまりの難しさにびっくりした。

This sentence is correct only in limited contexts.

It states the _definite fact_ that the father got surprised. As Derek Schaab
stated in [this
answer](https://japanese.stackexchange.com/questions/2524/when-to-
use-%E6%AC%B2%E3%81%97%E3%81%8C%E3%82%8B-instead-
of-%E6%AC%B2%E3%81%97%E3%81%84/2538#2538) accurately,

> Japanese has a curious unwritten rule which states, in essence, that you
> cannot presume to know the intimate details of a third person's mental
> state.

Therefore, if the author of the sentence _is_ the father and using 父 as a
first-person pronoun, then the sentence is fine, but otherwise you need ようだ.

By the way, for some reason, the sentence becomes natural if it ends with
びっくりしていた instead of びっくりした when 父 refers to the author’s father. I do not know
why.

