Both all together and altogether are correct but have different meanings. An easy way to distinguish between the two is to remember that all together typically applies to multiple people or things, and all together usually applies to one entity or action that is examined as a whole.

We call a person who buys a buyer, but why do we call a person who lies (tells a false statement) a liar, not a lier? We simply add an “er” to “buy,” but why does the same not apply to “lie”?

Complement means to complete or enhance something else, while compliment means to express praise and admiration.

Bear with me is the correct phrase. Although bear and bare are homophones that sound and are pronounced the same, they are words with different meanings.

Although the two words concave and convex look similar, they have opposite meanings. An object that is concave has a surface that curves inward. Meanwhile, an object that is convex has a surface that protrudes outward.

Everyday (without the space) is actually an adjective that describes the noun that follows. For example, "You could have an everyday routine and face everyday problems." Everyday is describing the nouns routine and problems here.