Why do we need する in 送ったりする時

[code]

    切手を買ったり荷物を送ったりする時に行く所です
    
[/code]

It seems that the verb before 時 is in the dictionary form. 送ったり is already a
verb. Does that mean we always need する if we change the form of the verb?




Not quite sure what you are asking here, but this is a very standard sentence
structure.

> Verb phrase X in past tense + り + another verb phrase Y in past tense + り +
> ... + する  
>  Do things like X and Y

The する is part of this fixed grammar pattern. It is the **do** part of "do
things like...". It is not generally applicable to any other verb
manipulations. You can conjugate this する according to your needs, so it would
become した if you wanted to day " **did** things like ...".

Not sure what you meant by "送ったり is already a verb". It is the verb 送る
(dictionary form) conjugated to the past tense (送った) with り added on to make
the たり form.




Not quite sure what you are asking here, but this is a very standard sentence
structure.

> Verb phrase X in past tense + り + another verb phrase Y in past tense + り +
> ... + する  
>  Do things like X and Y

The する is part of this fixed grammar pattern. It is the **do** part of "do
things like...". It is not generally applicable to any other verb
manipulations. You can conjugate this する according to your needs, so it would
become した if you wanted to day " **did** things like ...".

Not sure what you meant by "送ったり is already a verb". It is the verb 送る
(dictionary form) conjugated to the past tense (送った) with り added on to make
the たり form.

