In Korean, "mother" is "eomeoni" (어머니). The equivalent term used in the family context (something like "mom") is "Umma" (엄마). Read on for information on pronunciation and context!
Steps
Step 1. Repeat the word "Umma" (엄마)
It is pronounced "Om-ma". It is the familiar form of "mother", with a similar meaning to "mom". You can use this word when addressing your mother directly or when you talk about her affectionately to someone else.
Keep in mind that this is the transposition of a Korean word into the Latin alphabet. Writing in syllables necessarily renders the pronunciation of native speakers rough. Also, some pronounce "umma" as "iomma"
Step 2. Repeat the word "Eomeons" (어머니)
It is pronounced indicatively "a-ma-ni". It is the formal term for "mother". You can use this form by talking about your mother to someone else or referring to someone else's mother, whom you don't know.
Step 3. Listen to the pronunciation of a native speaker
If you know a Korean, ask him to say the word in front of you and correct your diction. Otherwise, search YouTube videos, or search for recordings or examples on the internet. There are several tutorials that help you perfect the pronunciation of foreign words. You will find that it is much easier to imitate a language if you hear it spoken aloud.
To get a feel for the rhythm of the language, try watching movies and shows in Korean. You may not necessarily catch the word "mother" often, but you may find that pronouncing the word naturally is much easier if you understand the context
Step 4. Start slow and then increase the speed
The inflection may be different than what you are used to, so take your time and try to grasp each syllable distinctly. When you feel confident that you can pronounce the individual syllables correctly, put them together. Quickly pronounce: "Umma". Native speakers tend to say the word quickly, so you too will sound more authentic if you do the same.
Step 5. Consider learning Korean
Even if you pronounce the word fluently, you run the risk of calling your mother "umma" out of context. But if you speak the language a little, you are able to use the word more effectively. Search for resources online, buy a basic Korean textbook, and make sure you practice the language whenever you have the opportunity.