As and like both translate to “comme” in French, which explains the almost systematic confusion among French-speaking learners. However, these two words are not used in the same sentence structures or in the same contexts. As is one of the most versatile linking words in English, capable of expressing a role, a comparison of equality, a cause, or a simultaneity, while like remains above all a tool for comparison by resemblance.
The basic rule to remember
| Word | Construction | Register |
|---|---|---|
| As | Followed by a subject and a verb, or by a noun to express a role | More formal, professional |
| Like | Followed directly by a noun or a pronoun | More informal, everyday language |
A simple trick can help you decide in most cases: if a full clause with a subject and a verb follows the word, as is required. If only a noun or a pronoun follows, like is the right choice.
As: expressing a role or a function
As translates to “in the capacity of” when it comes to describing the role, profession, or function of someone or something. This usage never accepts like as a substitute, even in informal register.
| English | French |
|---|---|
| She works as a teacher. | She works as a teacher. |
| He acted as the team leader. | He acted as the team leader. |
| As your brother, I must tell you the truth. | As your brother, I must tell you the truth. |
| They use it as a tool. | They use it as a tool. |
As: the comparison of equality (as…as)
The structure as + adjective or adverb + as is used to express equality between two elements, the equivalent of the French “aussi… que”.
| English | French |
|---|---|
| She is as talented as her brother. | She is as talented as her brother. |
| This house is as big as a ship. | This house is as big as a ship. |
| You can’t speak English as well as I do. | You can’t speak English as well as I do. |
As: comparing a full action (subject + verb)
When the comparison relates to a complete action rather than a simple noun, as becomes mandatory, and like remains incorrect in careful English.
| English | French |
|---|---|
| Do it as I showed you. | Do it as I showed you. |
| No one makes pastries as my aunt does. | No one makes pastries as my aunt does. |
| I like being on my own, just as you do. | Like you, I like being alone. |
As: expressing cause or simultaneity
| English | French |
|---|---|
| As I have the flu, I can’t come to work today. | As I have the flu, I can’t come to work today. |
| As it was cold this morning, I took a scarf. | As it was cold this morning, I took a scarf. |
As if and as though: as if
These two expressions, strictly interchangeable, are used to describe a hypothetical situation or a deceptive appearance.
| English | French |
|---|---|
| He acts as if he owns the place. | He acts as if he were the owner. |
| The sky looked as though it was on fire. | The sky looked as if it were on fire. |
| He started yelling as if he was the boss. | He started yelling as if he were the boss. |
Like: comparing by resemblance (preposition + noun)
Like expresses a resemblance between two elements, without ever introducing a conjugated verb right after. This usage remains more common and more natural in spoken English than as in the same context.
| English | French |
|---|---|
| I have a cat like yours. | I have a cat like yours. |
| She has beautiful eyes, like her mother. | She has beautiful eyes, like her mother. |
| She’s just like her brother. | She is exactly like her brother. |
| He runs like a cheetah. | He runs like a cheetah. |
Like with sense verbs
Look, sound, feel, smell and taste almost always pair with like rather than as to express a sensory impression.
| English | French |
|---|---|
| It looks like rain. | It looks like rain. |
| Your cake smells like chocolate. | Your cake smells like chocolate. |
| This tastes like vanilla. | This tastes like vanilla. |
| She looks like her mother. | She looks like her mother. |
Like to give an example
| English | French |
|---|---|
| There are beautiful places to see in Paris, like the Eiffel Tower. | There are beautiful places to see in Paris, like the Eiffel Tower. |
| You can do many things, like visiting museums. | You can do many things, like visiting museums. |
Such as remains the more formal alternative to like in this specific function, especially in formal writing.
The common pitfall: never put like before a subject and a verb
| Incorrect | Correct |
|---|---|
| He sings like he’s a professional. | He sings as if he’s a professional. |
| She looks as her mother. | She looks like her mother. |
| He works like an engineer. | He works as an engineer. |
This rule has an important exception in informal American English, where like increasingly replaces as before a subject and a verb, including in phrases such as “like I said” instead of “as I said”. This usage, long considered incorrect, has become widespread and is also gaining ground in informal British English. However, it remains inadvisable in writing or in professional contexts, where the strict distinction between as and like continues to apply.
Summary table
| Use | Word to use | Example |
|---|---|---|
| Role, function, occupation | as | She works as a doctor. |
| Comparison of equality (as…as) | as | As tall as his father. |
| Comparison of an action (subject + verb) | as | Do it as I told you. |
| Cause, simultaneity | as | As I was tired, I left early. |
| Hypothetical situation | as if / as though | He acts as if he knew. |
| Resemblance (preposition + noun) | like | She’s like her sister. |
| Sense verbs | like | It tastes like honey. |
| Giving an example | like / such as | Cities like Paris. |
In summary
As is used for roles, comparisons of equality, comparisons of full actions, and cause relationships, while like is reserved for comparisons of resemblance followed by a simple noun or pronoun, as well as for sense verbs. Remembering what follows the word in the sentence, a noun alone or a full clause, remains the most reliable reflex to choose between the two without hesitation.
