Relatedness of languages: 
The hypothetical macrofamily of Borean languages
My Amazon KDP e-books in English look for common roots of the oldest words (so far released: STONEHILL TOP MOUNTAINTALK CALL LANGUAGECUT AXE SAW FILEFIRE BURN KINDLE IGNITEmore to come in the same series 123+ Words from the Proto-World).

We are already able to read out of genes that the whole mankind has common ancestors. Some of us can find a common ancestor in not too distant past while others long time ago. But we all have common ancestors and it is possible today to constuct genealogical trees of various ancestor lines (more about this in my book in Czech language Who we are and where we come from. Unsuspected connections of the search for ancestors). We can not just construct trees of genealogic lines, but even their paths around the globe. 
The languages of today have similar trees. Some time ago where all lines of ancestors of all people meet, a common proto-language must have existed. This is sometimes called Proto-Sapiens or Proto-World. This proto-language gradually branched out. 
Even in the most distant, ie. Sub-Saharan languages of Africa, we can find some words showing similarities with equivalents in most languages of the world. These are usually words used every day, like daddymum, water, stone and similar. Most of vocabulary and grammar differs today, however. So if we separate off the most distant languages of Sub-Saharan Africa and Australian Aboriginal languages, we get a bit closer group of so called Borean languages, where there are more similarities than just a few.
Borean, Nostratic and Eurasiatic languages
The word Borean is derived from the Greek word for NORTH. This hypothetical macrofamily includes most languages of the world and the relationships of the individual languages and subgroups within it are graphically depicted in the below images. Within its framework, there is a narrower proposed macrofamily of the Nostratic languages and within its framework, an even closer group of Eurasiatic languagesEuroasiatic subgroup already includes our - 100% proven - subgroup or family of Indoeuropean languages, together with the Altaic, Uralic (Finnougric) macrofamily etc. More about this is in the three images below. They are a simplified and slightly improved version of this tree presented on the web concerning Borean languages. My adjustments take care of some minor errors in the original tree, e.g. where Upper Sorbian and Lower Sorbian are not distinguished and put simply as Sorbian. The first small language (small by the number of speakers today) is more similar to Czech while the other is more similar to Polish, it is not possible to put them as one language. I also omitted a few less well known languages.
Controversy around macrofamilies
Borean languages are a hypothetical group of most languages in the world, whose relatedness was proposed by some linguists (e.g. Sergey Starostin, his time axis) but others completely deny it. The same can be said about the Nostratic macrofamily and even about the Eurasian family. Disputes are being led about the existence of Altaic group of languages. 
Personally, based on better or less good knowledge of about 15+ very diverse languages, I have no doubts that all languages of the world are related and come from their common root in the deep past. The real tree, however, could be different from this constructed tree to some extent. For example, its placement of Basque may be erroneous. With regard to similarities in vocabulary it seems improbable to me that Basque would not belong to the narrower Eurasiatic macrofamily. There are too many lexical similarities with other Eurasiatic languages (e.g. Proto-Basque numerals 1, 2, 3 are almost unbelievably similar to their reconstructed Altaic counterparts, many basic words of Basque are similar to Finnougric, Japanese and even Slavic words, while probability of hundreds of basic (and the oldest) words being all borrowed is negligible. This is what makes me think there must be a narrower relatedness of Basque to Macroaltaic, Indoeuropean and Uralic/Finnougric group. 
Speaking is older than Homo sapiens sapiens
People did not start to speak out of nothing into the state of using language in many places independently on each other, it does not make sense linguistically, genetically nor anatomically. Most probably, language was used not just by our species of Homo sapiens sapiens, but even Neanderthals and Denisovans (both species are also ancestors of all of us). Even they had anatomical preconditions for speaking and this is why there is no reason to doubt that they spoke. Most likely, language is an older phenomenon that the Homo sapiens sapiens species. 
Despite individual uncertainties or possibilities of different connections, majority of the proposed tree of Borean macrofamily probably makes sense. According to proponents of this theory, it comprises most languages of Europe, Asia, Northern Africa and original Native American languages of both Americas. Next to our Nostratic macrofamily, there are Dene-Caucasian, Amerind and Austric macrofamilies grouped together as Dene-Daic. A hypothetical common Borean proto-language could have existed sometimes around 15 to 20 thousands years ago, somewhere in Eurasia. It could also have been somewhat deeper in the past.
The three connected images are depicted below.
KAREL MACHALA, 6/2017 (split into Czech and English version: 10/2020)
P. S. Very interesting article to read: Mehmet Kurtkaya on connections between ancient languages, Indoeuropean-Sumerian-Ugur-Turkish, e.g. G-R-/T-R- word root in Ugric, Greek, Turkic, Hurrian etc. The Eurasiatic connection is easy to see once we know old words and grammar structures from these languages..

Tree of languages - Hypothetic BOREAN MACROFAMILY * Strom jazyků - hypotetická BOREJSKÁ JAZYKOVÁ MAKRORODINA