Question: Can anyone explain me the difference between "walks," "walked," and "will walk"?

Example:

> 
> Martha loves exercising so she **walks/walked/will walk** everywhere she goes.
> 
> 
>

Answer: 
Those are three different tenses.

> 
> **walks** (third person singular present tense; regular action or habit)  
> 
> — *She **walks** everyday.*
> 
> 
> **walked** (past tense; completed action on a specific time)  
> 
> — *She **walked** yesterday.*
> 
> 
> **will walk** (future tense; planned stuff to do in the future)  
> 
> — *She **will walk** within two days.*
> 
> 
>
*walks* - present simple tense (3rd person singular) 

*will walk* - used to refer to future time (often called the future tense) 

*walked* - past simple tense (it's not grammatical in your sentence, since *Martha loves exercising* is in the present tense.)

For more information, I highly suggest you read a basic grammar site about verb tenses. You can start [here on this page](https://www.englishclub.com/grammar/verb-tenses.htm) at the English Club.