Language complexity and its transfer between languages

Hello people!

I'm studying cross linguistic influence, specifically the transfer of meaning between languages, and wanted to ask you a few things about your language learning experience.

Often researchers look at the mistakes that learners make when speaking or writing in English and through error analysis they determine if these mistakes are due to transfer from the learner's first language. Some features of English can be difficult because they are different or simply don't exist in the learner's first language (e.g. phrasal verbs). 

What interests me is the opposite! That is when the learner's first language is more 'complex' or contains a feature that is not present in English and can not be accommodated into English.
(e.g. catergorisation of innanimate nouns into gender groups (SPA - la mesa, ITA - il tavolo, etc.)

 

Do you have any other examples of this??? Specifically when there is no 'space' for a linguistic feature in English...I'm not so interested in so called untranslatable words, such as 'deja vu'.

All comments welcome!
Thank you

Which other languages are without gender in nouns (as with English)? Does your first language have grammatical gender for nouns? Does it have masculine, feminine, neuter groups? Do you find it strange when you use English and you can't include this feature?! I'd love to hear your comments :)