Spanish verbs Dejar vs Dejarse (pronominal verbs)

There is often confusion about whether to use the verb dejar or dejarse. They have different meanings depending on how they are used.

Dejar: When referring to things

1. dejar (algo a alguien) = to lend

When you lend something to someone:

Bear in mind that in this case you will often find an indirect object pronoun (le, nos) to indicate who the thing is lent to. These are not reflexive pronouns, but rather indirect object pronouns.

2. dejarse (algo en algún lugar) = to leave (something behind) 

To express that you forget something / leave something behind, somewhere, by accident.

Here we need the reflexive pronouns: me, te, se, nos, os, se

3. dejar (algo en algún lugar) = to leave [something somewhere on purpose) 

To express that you leave something somewhere on purpose, not by accident. Dejar is used here with no reflexive pronoun. In this case it is not accidental. For example:

 4. dejar (algo) + adjective/adjectival phrase = to leave something in a certain way

To express leaving something in a certain way/state, we can use dejar as shown in the following examples:

 

Dejar: When referring to people

1. dejar (a alguien) = to leave/abandon (someone)

The person who is abandoned is indicated with a + person or a direct object pronoun (me, te, lo, la, nos, os, los, las).

2. dejar (a alguien hacer algo) = to let /allow (someone do/to do something)

Notice that this meaning always requires either a direct object or an indirect object pronoun indicating who is "allowed to do" something. 

The tendency is to use an indirect object pronoun (me, te, le, nos, os, les) if the second verb is transitive. However if the second verb is intransitive, the pronouns used for the person are the direct object pronouns (me, te, lo, la, nos, os, los, las).

3. dejar [generally in the imperative] + que = let me/us/him/her/them do something  

Frequently the verb does not use the pronoun, but they could also be used with no change in meaning:

4. dejar (a alguien) + adjective/adjectival phrase= to leave someone in a certain way/state

As in previous point 4, to express leaving someone in a certain way/state, we can use dejar as shown in the following examples:

5. dejarse = to let yourself go (to neglect your appearance)

We use dejarse to express that someone has neglected his/her appearance. It often comes accompanied by words like "mucho", "un poco", "completamente".

6. dejarse llevar [por algo/alguien]= to let yourself go

We also use dejarse llevar to express "to let yourself go" in the sense of "relaxing and going with the flow". Have a look at these examples:

Sometimes it means "to get carried away [by something]". For example:

Bear in mind that there might be other uses of dejar that have a different nuance, or are used in set expressions with a particular preposition, for example:

Dejar en paz = to leave alone

Dejar [algo] para ... = to put aside for...

See also Using dejar de + [infinitive] = to stop doing something/to give up something