Fill them up vs Pack

When to use each in English, with meaning, register, and examples.

Fill them up

Top 2,000 (common)

Pack

Top 1,000 (very common)A2verb
Most common: Pack
 Fill them upPack
Pronunciation🇬🇧 //fɪl ðɛm ʌp//🇺🇸 //fɪl ðɛm ʌp//🇬🇧 /["/pæk/","/pæks/","/pækt/","/ˈpækɪŋ/"]/🇺🇸 /["/pæk/","/pæks/","/pækt/","/ˈpækɪŋ/"]/
MeaningMake something full, especially with a liquid.To put things into a bag or container.
ExamplePlease fill them up with water before the party starts.I need to pack my clothes for the trip.
RegisterNeutralNeutral
How commonTop 2,000 (common)Top 1,000 (very common)
CEFR level-A2
Part of speechverb
Collocationsfill them up with water, fill them up to the brim, fill them up completelycarefully, neatly, tightly, in, into, carefully, neatly, tightly, in, into, into, be packed full of something, be packed out, be packed to bursting
Antonyms-unpack, scatter, disorganize
Common mistakesOmitting 'up' (e.g., saying 'fill them' instead of 'fill them up')., Using it with non-containers (e.g., 'fill them up' for ideas instead of physical objects).'Packed' vs 'pack' confusion with verb tense., Using 'pack' without an object when it should include one., Confusing 'pack' with 'package'.
Usage notesUsed for actions involving containers or spaces. Common in everyday conversation, less formal than 'fill to capacity'.Used in both casual and formal contexts. It's common to use 'pack' when referring to preparing travel bags or organizing items for moving. Avoid using in overly formal or academic contexts.

See it in real clips

Fill them up
Pack

Frequently asked questions: Fill them up vs Pack

What's the difference between Fill them up and Pack?

Fill them up: Make something full, especially with a liquid. Pack: To put things into a bag or container.

Which is more common: Fill them up and Pack?

Pack is the most common in everyday English.

Can you show an example of each?

Fill them up: Please fill them up with water before the party starts. Pack: I need to pack my clothes for the trip.

Can I use Fill them up and Pack interchangeably?

Not always. Fill them up and Pack are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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