“Touchdown” and “touch down” differ mainly by grammatical function. Cambridge records the closed form as a countable noun for landing and sports senses and the two-word form as a phrasal verb, including aircraft landing and rugby uses.
ReviewedEvidence2 sourcesSectionEnglish Usage
Quick answer
Use “touchdown” as a noun and “touch down” as the phrasal verb. A plane can “touch down”; its landing is a “touchdown.”
Key details
Confusion Familyword-boundary
Rule Familynoun versus phrasal verb
Termstouchdown, touch down
Variant ScopeClosed touchdown is a noun; spaced touch down is a phrasal verb.
Further guidance
Core difference
Use “touchdown” as the noun for a landing or a scoring event; use “touch down” as the verb for landing or, in rugby, grounding the ball.
Fast Test
If the expression can be inflected as “touched down” or “touching down,” use the two-word verb.
Usage Boundary
Keep the grammatical role clear: the closed noun and spaced phrasal verb can occur in closely related landing or sports contexts without being interchangeable spellings.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
“Lockdown” is the noun for an official restriction or state of restricted movement, while “lock down” is the corresponding phrasal verb. Sentence function determines the spacing.
“Phase out” and “phaseout” differ by grammatical function. Merriam-Webster records “phaseout” as the noun and “phase out” as the corresponding verb, with forms such as “phased out” and “phasing out.”
“Turn off” is the two-word phrasal verb for switching something off, leaving a road, or causing loss of interest. The corresponding noun appears as closed “turnoff” in American usage and also as hyphenated “turn-off” in Cambridge.
Standard English writes “a lot” as two words for a large amount, number, frequency, or degree. “Alot” is a common misspelling in this sense; it should not be confused with the separate verb “allot.”
“Any more” can be a determiner for additional quantity and an adverb meaning “no longer.” Cambridge notes that the one-word adverb “anymore” is especially common in American English, while the determiner remains two words.
“Anyone” is one word when it means any person. “Any one” is written as two words when the construction refers to a single member of a larger set, including the common pattern “any one of …”.
