Hello, dear student! Today we will discuss some words which you should memorize. Let me recall, when we decline a noun in cases in the Russian language, we look at the endings which define the case. But there is a range of words which cause difficulties in the understanding of the cases.
The group of words of feminine gender which includes:
Имя - (о чём?) имени - именах (plural form) - [Imya -imeni- imenakh] Name/names
Дочь - (о ком?) дочери - дочерях (plural) - [Doch'- docheri- dochiryakh] Daughter/ daughters
Время - (о чём?) времени- временах (plural) - [Vremya -vremeni-vremenakh] Time, in the Russian language there is also a plural form of this word.
Мать - (о чём?) матери- матерях (plural) - [Mat'- materi- materyakh] Mother/mothers
There are also such exceptions, as:
Лес - (в чём?) в лесу [les - v lisu]
В лесу растут грибы [V lisu rastut griby] - There mushrooms growing in the forest.
Аэропорт - (в чём?) в аэропорту [aehraport - v aehrapartu]
В аэропорту сейчас очень много самолетов [V aehrapartu sijchas ochen' mnoga samalyotaf] - There are lots of planes in the airport.
Сад (в чём?) в саду [sad - v sadu]
Дети играют в саду [Deti igrayut f sadu] - Children play in the garden
Шкаф (в чём?) в шкафу [shkaf - v shkafu]
В её шкафу много одежды [V eyo shkafu mnoga adezhdy] - There is much clothes in her wardrobe.
Пол (на чём?) на полу [pol - na palu]
На полу валялись чьи-то вещи [Na palu valyalis' chyi-ta vesshi] - There was somebody's stuff lying on the floor.
As these examples show, nouns in the dative case have the ending -у [u] that is untypical for the prepositional case. Thus, if you do not know these exceptions, you can easily be confused and define the declension incorrectly.