For a loved one:
* Mpenzi: This is the most common word for "lover" or "sweetheart". It's used for romantic partners and is generally considered affectionate.
* Moyo wangu: This literally translates to "my heart" and is a very affectionate term for a loved one.
* Upendo wangu: This translates to "my love" and is another affectionate term for a loved one.
For someone you care about deeply:
* Mpendwa: This is a more general term for "beloved" or "dear" and can be used for anyone you care about, not just a romantic partner.
* Rafiki yangu: This means "my friend" and can be used affectionately towards someone you're close to.
For a child:
* Mtoto wangu: This means "my child" and is a very affectionate term for a child.
The best way to choose the right word is to consider the relationship between you and the person you are talking to.
For example, if you are talking to your partner, you might use "Mpenzi" or "Moyo wangu". If you are talking to a friend, you might use "Rafiki yangu". And if you are talking to a child, you might use "Mtoto wangu".
It's also worth noting that Swahili is a rich and nuanced language, and there are many different ways to express affection. The best way to learn is to practice and listen to how native speakers use these words in different contexts.