Construction of the word "подтвержда́ть"

Question

I've heard that in Russian the words are generally constructed with a root and have specific prefixes or suffixes added to them (I think the proper linguistics term for this is derivational morphology)...

I'm trying to work out the construction of "подтвержда́ть " (imperf). From wikipedia I see that the etymology of the word is as such:

подтверди́ть +‎ -а́ть

And the etymology of подтверди́ть is

под- +‎ твёрдый +‎ -ить

под- (takes adjectives, produces adverbs) and means: completely твёрдый means: hard or solid? ить: to

So the meaning is like "to be completely solid/to be completely firm"?

I'm interested to know how a native Russian speaker would break down this word into the seperate parts and explain it.

Answer 1

• под is a prefix with the general meaning of "sub", "under", however its meaning can vary greatly.

• твержд is a root, loaned from Church Slavonic (you can tell by the жд as the reflex of the original Proto-Slavic *-dj-, a native Russian word would have had ж).

• -ать is an inflexional ending, meaning this form is an infinitive

This word seems like a calque from Greek ἐπιβεβαιῶ "I confirm", from ἐπί "at" and βέβαιος "firm, steady".

Note that the English words "confirm" and "affirm" are Latin loanwords with the same structure.

Answer 2

Indeed, the root morpheme of подтверждать is твёрд ('solid') (which has твер(ж)д(ь) as allomorphs).

The prefix под- can be loosely interpreted as 'to add':

• мешать (mix) - подмешать (to mix in)
• нести (bring) - поднести (to bring in), etc

So the whole word подтверждать can be read as 'to add solidity/weight' (to a statement).

One other word with the same root is утверждать which has two meanings: 'to make a statement' and 'to approve / sign off'.