To what factors would someone attribute such an influence? To the Turkish conquests in Europe in the previous centuries perhaps?
No. The Turkic influence “happened” before the arrival of the Hungarians in the Carpathian Basin, when the Magyar tribes lived “together” with various Turkic tribes. Some words could be borrowed also during the Turkish conquest, of course, but this is statistically irrelevant. The
Turkic loanwords in Hungarian are typically not from
Turkish (language spoken in Turkey), but they come from
various Turkic languages and, according to phonetical correspondencies,
mostly from “
Chuvash-like” languages.
On the other hand, if we speak about similarities in grammar structures, then the subject is different.
Yes, the subject is different also because these similarities are present in other Uralic langages as well (including e.g. the Finnish that has not been exposed to Turkic/Turkish influence). These similaraties resulted in the theory of a possible Uralo-Altaic language family, but this theory is today rejected by most of the linguists for many serious reasons. However, these similarities cannot be expained “simply” by mutual influence, at least not during the last 3-5 (or even more) millenia.
Wikipedia gives the following distribution for the Hungarian language:
Uncertain: 30%
Finno-Ugric: 21%
Slavic: 20%
German: 11%
Turkic: 9,5%
Latin and Greek: 6%
Romance: 2,5%
Other: 1%
Other sources may give different values, but (as far as I know) the differences are not too relevant. So, I think, these numbers can be considered approximately valid.
On the other hand, these statistical data reflect rather the origin of the
word stems and not the whole existing lexicon of the language. From this point of view, the most “productive” words in Hungarian are those of Finno-Ugric origin as, according to various sources, more than 80% of the total lexicon of the modern Hungarian (including derived words, neologisms, compound words etc … ) seem to be of Finno-Ugric origin.
The great number of the words of uncertain origin is primarily due to the fact that the Hungarian is the oldest documented Uralic language (from the 10
th century A.D.) and there are not enough ancient written documents in other Uralic languages to be compared with ...
... My assumption was that the Hungarian vocabulary did not have so many influences from outside languages ....
Your assumption/observation is indeed valid to a great degree (especially for the last centuries), but not necessarily true for the origin of all the “historical" stems of the Hungarian language. Further details could be discussed in a separate (probably interesting) thread …