"I am thirsty."
Translation:Я хочу пити.
In Ukrainian, you don't talk about feelings like hunger, thirst, cold etc. "я маю". Every language has its own understanding about what can go with "have", and in Ukrainian things like hunger just never go with it. In Ukrainian "have" is usually used more literally about possession, and you can't possess feelings.
You can say "я відчуваю спрагу" - "I feel thirst", this will be right, but still a bit artificial. It's best to say "я спраглий", "я голодний" as well as "я сумний", "я веселий" - as if the feeling somehow modifies you. Or you can use the construction "мені хочетья пити", "мені хочеться їсти", though it's milder - if you want to drink, it doesn't necessarily mean that you are thirsty.