ようでは / ようじゃ

ようでは means "if things are like this": it picks out a situation the speaker disapproves of and says that, as long as it goes on, the result will be bad. It follows the plain form of a verb, usually a negative or a habit, and the second half is a warning or a criticism. ようじゃ is the spoken form.

The second half is the bad outcome: you can't, you won't, it's a problem. To say that something good will follow, use ば or たら.

• × 毎日練習するようでは、上手になる → 毎日練習すれば、上手になる

も often goes on the first half, as in かんたん簡単なもんだい問題も, "not even an easy problem": the failure is worse than it should be.

ようでは or ようなら

ようなら is a neutral "if it turns out that", often followed by advice. ようでは judges the person or situation and expects it to end badly.

After the ます-stem rather than the plain form, よう is a noun, "way of doing", and ようでは is a different pattern: そんないい言いようでは, "if you put it that way". Here the verb is always in the plain form: できないようでは, ちこく遅刻するようでは.