Yes, definitely.

Disclaimer
I am not nearly as proficient in classical Chinese, so my answer is limited to modern Chinese.

IMHO, 未 is more commonly seen in formal context and is often used with 曾 or 從, as in 未曾 or 從未.

For example,

單純的你，未曾憂鬱過。

You're such a simple person; you've never been depressed.

人生自古以來，從未順利。

Since the ancient times, life (of a human) has never been smooth.

Note that the adjectives act similarly to a verb, as suggested by WangYudong above. I don't think 長 and 短 are verbs per se.

Yes, definitely.

Disclaimer
I am not nearly as proficient in classical Chinese, so my answer is limited to modern Chinese.

IMHO, 未 is more commonly seen in formal context and is often used with 曾 or 從, as in 未曾 or 從未.

For example,

單純的你，未曾憂鬱過。

You're such a simple person; you've never been depressed.

人生自古以來，從未順利。

Since the ancient times, life (of a human) has never been smooth.

Note that the adjectives act similarly to a verb, as suggested by WangYudong above. I don't think 長 and 短 are verbs per se.

EDIT:
FYI, as FortCpp explained below, adjectives in such construct may actually be verbs.

Yes, definitely.

Disclaimer
I am not nearly as proficient in classical Chinese, so my answer is limited to modern Chinese.

IMHO, 未 is more commonly seen in formal context and is often used with 曾 or 從, as in 未曾 or 從未.

For example,

單純的你，未曾憂鬱過。

You're such a simple person; you've never been depressed.

人生自古以來，從未順遂。

Since the ancient times, life (of a human) has never been smooth.

Note that the adjectives act similarly to a verb, as suggested by WangYudong above. I don't think 長 and 短 are verbs per se.

Yes, definitely.

Disclaimer
I am not nearly as proficient in classical Chinese, so my answer is limited to modern Chinese.

IMHO, 未 is more commonly seen in formal context and is often used with 曾 or 從, as in 未曾 or 從未.

For example,

單純的你，未曾憂鬱過。

You're such a simple person; you've never been depressed.

人生自古以來，從未順利。

Since the ancient times, life (of a human) has never been smooth.

Note that the adjectives act similarly to a verb, as suggested by WangYudong above. I don't think 長 and 短 are verbs per se.