По сравнению с орхидеей кактус крепче и не вянет, даже когда почва сухая.

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Breakdown of По сравнению с орхидеей кактус крепче и не вянет, даже когда почва сухая.

• не: not
• когда: when
• даже: even

Questions & Answers about По сравнению с орхидеей кактус крепче и не вянет, даже когда почва сухая.

Why is it с орхидеей and not с орхидея?

Because the phrase по сравнению с requires the instrumental case.

So:

• орхидея = nominative singular
• орхидеей = instrumental singular

This is a fixed pattern:

• по сравнению с братом = compared with the brother
• по сравнению с прошлым годом = compared with last year
• по сравнению с орхидеей = compared with an orchid

So the ending -ей is there because орхидея has to be in the instrumental after с in this expression.

What does по сравнению с mean exactly, and is it the same as чем?

По сравнению с means in comparison with or compared with.

It is similar in meaning to using a comparative with чем, but the structure is different.

For example:

• Кактус крепче, чем орхидея. = The cactus is tougher than the orchid.
• По сравнению с орхидеей кактус крепче. = Compared with the orchid, the cactus is tougher.

The version with по сравнению с feels a bit more explicit and sometimes a bit more formal or explanatory. It sets up the comparison first, almost like giving the frame:

• As compared with the orchid...

So both are possible in many contexts, but they are not grammatically interchangeable word-for-word.