Overdue vs. overdo: how to tell them apart

The short answer

Overdue and overdo look almost identical, but they work in different ways. Overdue is an adjective that describes something past the time it was due, such as a library book, a payment, or a baby's arrival. Overdo is a verb meaning to do something to an excessive degree, like overdoing a workout or overdoing the seasoning in a dish.

• Overdue = adjective, past due
• Overdo = verb, to do too much

What overdue means

Overdue describes a noun that has not arrived, been paid, or been completed by its expected time. A library book that was due last week is overdue. A rent payment not made by the first of the month is overdue. The word can also describe something welcome but late, as in a long overdue vacation or an overdue apology.

Overdue always follows a linking verb like is, was, or become, or sits directly before the noun it describes. Correct: The rent is three weeks overdue. Correct: an overdue library book collects a small daily fine. Because overdue is an adjective, it never takes an object of its own; something simply becomes overdue over time.

What overdo means

Overdo is a verb that means to do, use, or exaggerate something beyond a reasonable point. You can overdo a workout by lifting too much weight, overdo the salt in a recipe, or overdo your enthusiasm in an email. The past participle, overdone, often describes food cooked too long, as in an overdone steak.

Overdo also works well with reflexive phrasing, since people often overdo it rather than overdo a specific noun. Correct: After the marathon, she admitted she had overdone it during training. Correct: Don't overdo the compliments, or they start to sound insincere. In each case, the verb signals that a reasonable limit has been crossed.

Common mix-ups

Because the two words sound similar in casual speech, writers sometimes swap them by accident. A sentence like his apology was overdo mixes up the adjective and the verb; the correct version is his apology was overdue. Likewise, don't overdue the exercise should read don't overdo the exercise, since overdo is the action word needed after the verb do.

Spell-check tools do not always catch this error, since overdo and overdue are both real words, just used in the wrong grammatical slot. Reading a sentence aloud and asking whether it describes timing or an action usually reveals the mistake immediately, since overdue answers when and overdo answers how much.

Overdue and overdo in everyday contexts

These words show up across very different situations. In finance, an overdue invoice may trigger a late fee, while a business that overdoes its marketing budget might overspend before the quarter ends. In the kitchen, a cake left in the oven too long is overdone, not overdue, since the cake did not miss an appointment. Recognizing the situation, whether it involves a deadline or an action taken too far, points straight to the correct word.

Remember it

A simple trick: overdue ends the same way as due, and both describe timing, like a due date or an overdue payment. Overdo ends like do, and both describe an action, since you do something and you can overdo it. Picture a clock for overdue and a checklist for overdo to keep the meanings separate.

• Overdue rhymes with due, about timing
• Overdo rhymes with do, about action