Allusion means to hint at something without explicitly naming it, while reference means to mention something.

Allude means to hint at something indirectly while elude means to escape or avoid. Illude, on the other hand, means to trick or delude.

While some say that alright is technically incorrect or non-standard, it’s perfectly fine to use alright in your writing, especially if your characters speak informally. If you’re writing a formal document or your characters speak formally, all right is a better option.

Aid can be a verb which means to help or a noun which means assistance. Aide, on the other hand, is a noun which refers to a helper or assistant.

Afterward means at a later time, while afterword is a concluding section of a book.

Affect is a verb meaning to influence or have an affect on something, while effect is a noun meaning a change resulting from an action. While effect can also be a verb, it’s likely the word you’re looking for is affected.

Adverse means to either prevent progress or be harmful, while averse refers to having a strong dislike or opposition to something. Adverse often refers to things instead of people but averse refers to people.

Adopted refers to the process of legally taking and bringing up a child or animal as one’s own. However, adopted can’t be used to refer to the ones doing the adopting. Adoptive should be used instead, which refers to the relationship by adoption.

Both admission and admittance mean the process of entering or being allowed to enter a place or organisation. Admission is often used figuratively while admittance has a more limited usage referring to physical entry.

Adequate refers to the acceptable quality or quantity of a thing in a particular circumstance, while sufficient means enough to meet a particular need. Enough, the most common for everyday purposes, means as much or many as required.