Both phrases are grammatically correct. The difference comes down to number — singular versus plural — and what you’re actually asking about.
The Simple Rule
Use what kind of when asking about one type or category.
Use what kinds of when asking about multiple types or an open range of possibilities.
That’s the core of it. Everything else is just context.
How Each One Works
What kind of treats the answer as a single category. You’re asking the person to name one type, or you expect the answer to fall into one group.
- What kind of music do you like?
- What kind of phone should I buy?
- What kind of dog is that?
In each case, the question points toward one type, even if the person could give a more detailed answer.
What kinds of opens the question to multiple categories. You’re inviting the person to list several types, or you already know the answer will involve more than one.
- What kinds of music do you listen to?
- What kinds of documents do I need to bring?
- What kinds of birds live in this region?
Here, the plural signals that you expect variety in the answer.
The Noun After the Phrase
One thing that trips people up: the noun that follows is almost always uncountable or a general category, so it stays the same regardless of which phrase you use.
What kind of food do you prefer?
What kinds of food do you prefer?
The word food doesn’t change. Only kind shifts to kinds.
This is true for most nouns in this construction: music, work, advice, support, information. They stay singular because they’re being used as categories, not counted items.
When the noun is countable, it usually goes plural after kinds of:
What kind of book is this?
What kinds of books do you read?
When the Difference Barely Matters
In everyday conversation, the two phrases often overlap. If someone asks “What kind of problems are you having?” or “What kinds of problems are you having?” — both feel natural, and neither is wrong. Native speakers use them interchangeably in informal speech without anyone noticing.
The distinction becomes more meaningful in writing, especially when precision matters. In a survey, a report, or any formal context, choosing the right one signals whether you’re asking for one answer or several.
A Quick Test
Before choosing, ask yourself: Am I expecting one type, or am I open to a list?
- Expecting one type → what kind of
- Open to several → what kinds of
If you’re genuinely unsure, what kind of is the safer, more neutral choice. It’s used more often in everyday English and sounds natural in nearly every context.
Common Mistake
Some writers use what kind of followed by a plural verb or plural noun when the meaning clearly calls for kinds of.
❌ What kind of exercises should I do every day?
✔ What kinds of exercises should I do every day?
The first version isn’t technically wrong, but if you’re asking about a range of exercises — not one specific type — kinds of fits better and reads more clearly.
Both phrases belong in standard English. Pick based on how many types you’re asking about, and you’ll always get it right.
Read more:
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- Window Seal vs Window Sill: Are They the Same Thing?
- Choose vs Chose: What’s the Difference?
- Weather, Whether, or Wether: Which Word Do You Need?
- Cancellation vs Cancelation: Which Spelling Is Correct?
It’s Afini, I am the author at Vocab press, a website focused on animal facts with clear visuals and simple guides. I research and share accurate, easy-to-understand information for readers of all ages. My goal is to make learning about animals fun, trustworthy, and simple. I follow fact-based writing and keep content updated, helpful, and people-first. Thank you for reading.
