What is the difference between よくない yokunai and だめ (dame)

Question

• よくない (yokunai) is defined as not good
• だめ (dame) is also defined as not good

Please could you explain the difference by explicitly making reference to the following examples:

Example 1a

dokomo yokunai desu
none of the places are good

Example 1b

kazoku wa saikin amari un ga yokunai.
Our family is not having much luck lately!

Example 2

It was a no good hotel.
Dame na hoteru deshita.

I know that 悪​い (warui) also means "not good", but it has the added meaning of bad, sinful, and so is a stronger form.

Please keep your explanation relatively simple as I am a beginner. Please could you make reference to the above examples.

Please also explain a general rule for knowing when to use one over the other.

Answer 1

だめ (dame) has a connotation of being not allowed, or so bad that it's just unacceptable. よくない (yokunai) is simply something that is the opposite of good いい(ii) and carries a bit less force.

• In the first example, you could substitute 'dame' for a more forceful tone.
• In the second example the use with 'amari' really requires a negative so 'yokunai' is the preferred option.
• In the third example you could use 'dame' as per the example and it would indicate that this hotel was really bad (and it would be assumed you didn't stay there, or wouldn't in the future as it is unacceptable). If you were to use 'yokunai' in this sentence it would suggest that it just wasn't great.

Answer 2

だめ is very strong. Literally it means "useless, no good" so 私(わたし)の日本語(にほんご)はだめです is actually pretty self-deprecating.

よくない is the negative of いい (as you probably already know). However it is only descriptive as in "not good" "not nice" etc.

Answer 3

On the surface, both 駄目{だめ} and 良くない{よくない} seem to have a similar meaning and use - both are adjectives of some kind and both seem to mean "not good".

駄目{だめ} is defined as a bad state or condition; ineffective as in wasteful of effort; a situation or condition upon which nothing can be done; a forbidden action :

• 暑さ{あつさ}で食べ{たべ}物{もの}が駄目{だめ}になる - Food turn bad in the heat
• いくら頼んでも{たのんでも}駄目{だめ}だ - It is useless no matter how much you ask
• これ以上{いじょう}歩け{あるけ}と言われても{いわれても}とても駄目{だめ}だ - It is impossible although it is said you can walk further
• ここでタバコを吸って{すって}は駄目{だめ}だ - It is forbidden to smoke here

良くない{よくない} from the adjective 良い{いい} is a generic way to say good :

• いい景色{けしき} - Beatiful landscape
• 割{わり}のいい仕事{しごと} - A fair job
• 態度{たいど}がいい - The attitude is good
• 君{きみ}に会えて{あえて}よかった - It was nice to meet you
• 帰って{かえって}もいい - You can leave (go home)

If we looks at your examples:

何処も{どこも}良くない{よくない}です

Using 良くない{よくない} in this sentence it means that no places are good. If we replace it by 駄目{だめ}, the meaning changes to "everywhere is bad". Note that 駄目{だめ} is also much more intense in meaning than 良くない{よくない}.

家族{かぞく}は最近{さいきん}あまり運{うん}が良くない{よくない}

This sentence means something like "the family isn't very lucky lately". In this situation, it is impossible to replace 良くない{よくない} with 駄目{だめ}. 駄目{だめ} is a name whereas 良くない{よくない} comes from an adjective - it would not fit in this sentence. To say your luck is bad you'd say 運{うん}が[悪​い]{わるい}. 運{うん}が駄目{だめ} would mean "I am bad at luck". It does sound right.

駄目{だめ}なホテルでした

This a proper use of 駄目{だめ}. 良くない{よくない} could also be used. However, 良くない{よくない} is much more indirect and polite. It would not carry the same meaning.