Tamarin and tamarind are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It’s suggesting what word you may want to save time, but quite often, its suggestions are pretty off base. They don’t help you out, but they do make you laugh.
Tamarin (tehmm-uh-rihnn) is a type of long-haired monkey with a nonprehensile (not a fully flexible, load bearing limb) tail native to South America.
Tamarind (tehmm-uh-rihnd) is an type of bean-shaped fruit.
The following story uses both words correctly:
Tamara was taking a break from her job at the zoo. She bought a tamarind smoothie and sat on a bench near the monkey enclosure. Her coworker Taylor came up to chat, and she set her drink down. Unfortunately a sneaky tamarin had been watching the whole time. Once she set the cup down and turned away, it reached for the cup through the bars of its cage. It ripped off the lid, and poured the cold gooey liquid into its gullet.