Грамматика русского языка. Часть 4. Безударные гласные. Глава 3. Безударные Э, У, и Ю. Значение ударения. Russian Grammar. Part 4. The Unstressed Vowels. Unit 3. The Unstressed Э, У, and Ю. Significance of the Stress.

The Unstressed Э, У, and Ю

These vowels remain practically the same, whether stressed or unstressed.

Examples:

это экран [eh-tuh ehk-rahn] this is a screen
умный дуэт [oom-nihy doo-eht] a clever duet
я мою каюту [yah maw-yoo kuh-yoo-too] I am washing the cabin

There was no real difference between the stressed and unstressed э, у, and ю in these phrases.

Грамматика русского языка. Часть 4. Безударные гласные. Глава 2. Безударные Ы, Е, И и Я. Russian Grammar. Part 4. The Unstressed Vowels. Unit 2. The Unstressed Ы, Е, И and Я.

The Unstressed Ы

The unstressed ы, usually occurring at the end of a word, sounds something like a cross between the uh-sound in lemon and the true sound of the ы.

Examples:

вазы [vah-zih] vases
куклы [kook-lih] dolls
красный [krahs-nihy] red (m.)
умный [oom-nihy] intelligent (m.)