Learn Spanish (Latin America): Estoy escondiendo el regalo.

Escondo can mean I hide or I am hiding in a general sense. However, using estar plus the gerund (estoy escondiendo) strongly emphasizes that you are in the exact middle of doing the action right now. This is the present continuous tense.

How do we form the word escondiendo?

The base verb is esconder (to hide). Because it is an -er verb, you drop the -er ending and add -iendo to make it a gerund (the Spanish equivalent of an -ing word). If it were an -ar verb, you would add -ando instead.

Why do we use estoy here instead of soy?

To talk about actions in progress using a gerund (an -ando or -iendo word), you must always use a form of estar. Ser is never used to build this continuous tense.

Why is there no yo (I) at the beginning of the sentence?

In Spanish, the verb usually tells you who is doing the action. Since estoy only ever matches with yo, the pronoun is already understood and can be left out to sound more natural.