Literal Meaning:

What = shénme 什么

is, are, was, were = shì 是

this = zhè 这

English Sentence:

What is this?

Mandarin Translation:

zhè shì shénme

Notes:

-Try to analyse the order of words in the English translation. It started with the word 'WHAT' (shénme)

-Try to analyse the Mandarin translation. It started with the word 'ZHÈ' (this)

-Try to imagine if we will translate the sentence in word-by-word manner:

What (shènme)    is (shì)     this (zhè)

-But if we will say shènme shì zhè in Mandarin to translate What is this, it will be incorrect.

Realization:

The order of words in English sentences is actually REVERSED in Mandarin grammar