Acclimate and Accumulate 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 suggests what word you may want to save time. It’s either correct, or couldn’t be more wrong.
Acclimate is a verb. It literally means to adapt to the temperature of a new environment. It can also mean adapting to cultural and behavioral norms, or learning to function by a new code of conduct.
Accumulate is a verb. It means to gather or collect things, and to continually gather them.
The following story uses both words correctly:
Akamu was doing all he could to keep his new job. He was learning to acclimate to a culture full of diverse personalities, while accumulating as much knowledge about the business in the shortest amount of time as he could. It was exhausting.