super market (supermarket)

Spacing and hyphens change meaning and ease of reading: supermarket ≠ super market; everyday ≠ every day; sign-up ≠ sign up. Below are clear rules, quick tests, many ready-to-use wrong→right pairs, and pasteable rewrites.

Quick answer

If two words name one thing, prefer the closed form (supermarket, website). If two words jointly modify a noun before it, hyphenate (short-term goals, well-known author). Keep words open when they form a verb phrase or an adverbial/time phrase (sign up, every day).

Closed for established compounds: supermarket, email, classroom.
Hyphenate compound adjectives before a noun: short-term goals, full-time job.
Leave phrases open when they act as separate words or as verb + particle: break up, look out.

Core explanation: open, closed, hyphenated

Open compounds are separate words that act together but remain independent (post office, sign up as a verb). Closed compounds are single words used as nouns or adjectives (supermarket, homework). Hyphenated compounds link words so they clearly act together as modifiers (deadline-driven report).

Use the modifier-before-noun test: if the phrase modifies a noun and appears before it, hyphenate to show the words form a unit.
When a one-word form is common in dictionaries, use the closed form.

Spacing decisions: quick tests

Run these tests in order: 1) Does it name one concept people treat as a single word? 2) Is it in current dictionaries as one word? 3) Does it act as a unit modifying a noun before it? If 1 or 2 yes → closed. If 3 yes → hyphenate. Otherwise keep it open.

If a one-word synonym fits naturally, the closed form likely applies (web site → website).
If the phrase answers "how often?" or describes time, keep words separate (every day).

Wrong: web site
Right: website
Wrong: everyday I go to work
Right: every day I go to work
Wrong: super market prices
Right: supermarket prices

Hyphenation rules (practical)

Hyphenate compound adjectives before the noun: well-known actor, long-term plan. After the noun, remove the hyphen in most cases: the actor is well known; the plan is long term. Hyphenate to avoid ambiguity, for compound numbers, and with prefixes that would form awkward doubles: re-enter, twenty-one.

Before noun → hyphenate. After noun → usually open.
Use hyphens to remove ambiguity (small-business owner vs small business owner).

Wrong: a deadline driven schedule
Right: a deadline-driven schedule
Wrong: The contract was long-term.
Right: The contract was long term.
Wrong: small business owner (ambiguous)
Right: small-business owner (owner of a small business)
Label: twenty one → twenty-one

Grammar traps that affect compounds

Compound errors often overlap with other grammar issues: adjective/adverb confusion, possessives, and verb vs noun forms. Decide first whether the phrase is a noun, an adjective, or a verb phrase, then pick a form that matches.

Be consistent across a document; consistency matters more than minor style choices.
Fix the compound and the related grammar at the same time for clarity.

Wrong: I go to gym everyday.
Right: I go to the gym every day.
Wrong: They had a break up last month.
Right: They had a breakup last month.
Wrong (ambiguous): The company's policy is strict. (if you meant policy in general)
Right: Company policy is strict. / The company's policy is strict. (choose by meaning)

Try your sentence

Test the whole sentence rather than isolating the phrase-context often makes the correct form obvious.

Examples you can copy (work, school, casual)

Below are ready fixes used in modern English. Copy the right-hand forms into your text.

Work
Wrong: e mail address
Right: email address
Wrong: time line of events
Right: timeline of events
Wrong: short term goals (before noun)
Right: short-term goals

School
Wrong: class room rules
Right: classroom rules
Wrong: home work assignment
Right: homework assignment
Wrong: test taking strategies
Right: test-taking strategies

Casual
Wrong: Let's go to the hang out tonight.
Right: Let's go to the hangout tonight.
Wrong: We were all together shocked.
Right: We were altogether shocked.
Wrong: She will re enter the chat.
Right: She will re-enter the chat.

Fix your sentence: five-step method + rewrites

Five steps: 1) Is it one concept? 2) Does it modify a noun before the noun? 3) Check a dictionary. 4) If unclear, hyphenate to remove ambiguity. 5) If awkward, rewrite the sentence.

Concrete rewrites to paste into your document:

Original: The team lead gave us a deadline driven schedule.
Rewrite: The team lead gave us a deadline-driven schedule.
Original: She went to the hang out with friends.
Rewrite: She went to the hangout with friends.
Original: Everyday I bring my lunch box.
Rewrite: Every day I bring my lunch box.
Original: We need a short term plan.
Rewrite: We need a short-term plan. (or) We need a plan for the short term.
Original: Sign up closes tomorrow.
Rewrite: The sign-up closes tomorrow. / Sign-ups close tomorrow. / You must sign up by tomorrow.
Original: They had a break up.
Rewrite: They had a breakup. / They broke up.

Memory tricks and quick checks

Mnemonic: "Before the noun = Bind with a hyphen." Quick check: replace the phrase with a single-word synonym-if it fits, the closed form probably applies.

Insert "the": if "the + phrase" sounds like a natural noun phrase, prefer the closed form (the breakup).
If the phrase answers "how often?" use separate words (every day).
If the first word is a verb and you mean the action, keep it open (break up); if you mean the result, close it (breakup).

Usage: "the break up" sounds wrong → use "the breakup".
Usage: "web site" → "website" if a one-word substitute fits.

Similar mistakes to watch for

Watch its vs it's, prefix hyphenation (re-enter vs reenter), and noun/verb distinctions (sign-up vs sign up). Brand and tech terms often shift over time (e-mail → email).

Pick a dictionary or style guide and apply it consistently across a document.
If a compound is still debated, rewrite the sentence to avoid the choice.

Wrong: It's color was faded.
Right: Its color was faded.
Wrong: They will re enter the building.
Right: They will re-enter the building.

FAQ

Should I write supermarket as one word or two?

Supermarket is standard as one closed word. Replace "super market" with "supermarket" in your draft.

When do I hyphenate compound adjectives?

Hyphenate when the compound adjective appears before the noun it modifies (a well-known author). After the noun, hyphens are usually unnecessary (the author is well known). Use hyphens to prevent misreading.

Is email hyphenated or one word?

Email is now commonly one word. E-mail is older but still accepted in some houses styles. Prefer email unless your style guide says otherwise.

How do I decide between everyday and every day?

Everyday is an adjective meaning commonplace (everyday tasks). Every day means each day (I walk every day). If "each" can replace "every," use every day.

Can a grammar checker fix these issues?

Checkers catch many errors but sometimes miss context or house-style choices. Use a checker for a first pass, then apply the quick tests above or rewrite for clarity.

When in doubt, rewrite or check a dictionary

A short rewrite usually clears meaning and removes style debates. For quick second opinions, consult a current dictionary or your project's house style and apply choices consistently.