this English construction is anything to go by
Depends on your goal. If you aim at "literature translation" - at a smooth naturally sounding RETELLING - then this construction surely is "to go by", but that would make the syntax comparison pointless. Then whether your aim would be "word to word matching", a reproduction of the language mechanics barebones in another more familiar language, even if the outcome would sound awkward and would but never be used in actual conversations, then that construction obviously does not fit.
I feel like the most verbatim translation of the 2nd part would be using "the very" or "himself" expressions.
Frankly, the first part of your example is not needed to make a "minimal verifiable example" as they say in some other StackExchange forums :-D
The core question revolves around "Это Борис впустил нас". Technically, even "нас" is not needed here, just the phrase would sound very awkward without it. If chosen so, to yet reduce boilerplate/noise, we could minimize the phrase yet further up to "Это Борис сделал" to use as neuter and minimal verb as possible.
So, I would go on with "Это Борис впустил нас".
Now you map it to English "It was Boris, who let us in" and feel confused, because this English counterpart is actually two sentences fused together, a so called "complex sentence". And translating it back to Russian, if verbatim, would require a 2-parts complex sentence too.
It was Boris, who let us in ==> То был Борис, кто впустил нас.
Now, this English expression is proper mapping for "literature translation" which is "retelling". But it is not the verbatim "literary" translation.
For word-to-word attempt we need some English phraseology, that anchors the attention to some specific term, exaggerates its importance, without spawning an extra sentence.
"Это Борис впустил нас".
At glance, I can see two options for it.
- one way to "underline" some term is appending xxxxx-self/xxxxx-selves to it.
"Boris himself let us in".
This, however, has a specific connotation, uncalled for. It emphasize some kind of worshipping, kissing up to. It could be said with some fans daring to ring on some super-star doorbell, and that superstar blessed them with his own descending.
That is not always so, if I imagine some possible interrogation scene from a detective book, then "Boris himself let us in" would sound much differently, as framing the said Boris. So in such a context this would be probably the fitting way to translate the original sentence. But only in this kind of a very specific, narrow context.
- The more universal option to map such a phrase to I believe would be using "the very" expression. That would probably not be met in real life spoken English. But for the "technical" goal of making word-to-word comparison and feeling the internal mechanics of the language conveying ideas, I guess it would be the most fitting mapping.
- used to emphasize that you are talking about one specific thing or part and not another
- 3 — used as an intensive especially to emphasize identity ·before my very eyes
- 5 : being the same one : selfsame ·the very man I saw
That way the mapping I feel would be "mechanically" proper would be this:
"Это Борис впустил нас" ==> "The very Boris let us in".
I have strong doubt whether "the very" construct in English can be applied to personal names and for natural way of language "it was him, who..." pattern feels better. However if we sack the English correctness for the sake of representing underlying mechanics of Russian then my gut feeling tells me those two constructs as reference points.
Now, your original example using those constructs seems to be "at low level" mapped verbatim way like that:
- Его зовут Борис, это он впустил нас в дом.
- They call him Boris, he himself let us into the house.
- They call him Boris, the very he let us into the house.
Those phrases are totally non-English and sound double plus awkward. Because they seek to word-for-word mapping of the entire rather complex language structure, and thus amount of boilerplate noise unrelated to the core question becomes overwhelming. Which was why I chosen above to strip your example of everything I felt was not immediately related to the problem at hands.