Question

el participio presente (p. 209)
the present participle is used to talk about actions that are in progress at the moment of speaking. to form the present participle of -ar verbs, add -ando to the stem. for -er and -ir verbs, add -iendo to the stem.
cantar: cantando insistir: insistiendo tener: teniendo
the present participle is frequently combined with the present tense of estar to talk about what someone is doing, or with the imperfect of estar to talk about what someone was doing.
estoy cortando el césped. i am mowing the lawn.
los niños estaban haciendo sus quehaceres. the kids were doing their chores.
a. write the ending of the present participle for each of the following verbs to say what the following people are doing while you’re at school. follow the model.
modelo (sacar) el fotógrafo está sacando fotos.

1. (trabajar) el agente de viajes está trabaj____ en su oficina.
2. (beber) el entrenador está beb____ agua.
3. (hacer) el científico está hac____ un experimento.
4. (escribir) el reportero está escrib____ un artículo.

only -ir stem - changing verbs change in the present participle. in the present participle, the e changes to i and the o changes to u.
servir: sirviendo dormir: durmiendo despedir: despidiendo
b. write the present participles of the verbs in the chart below. the first row has been done for you. remember that -ar and -er stem - changing verbs have no stem changes in the present participle.

-ar, -er	present participle	-ir	present participle
sentar	1. ____	sentir	5. ____
contar	2. ____	morir	6. ____
volver	3. ____	preferir	7. ____
perder	4. ____	dormir	8. ____

Explanation:

Part A

1. (trabajar)

Step1: Identify verb type

"trabajar" is an -ar verb.

Step2: Apply -ar verb present participle rule

For -ar verbs, add -ando to the stem. The stem of "trabajar" is "trabaj", so add -ando.

Step1: Identify verb type

"beber" is an -er verb.

Step2: Apply -er verb present participle rule

For -er verbs, add -iendo to the stem. The stem of "beber" is "beb", so add -iendo.

Step1: Identify verb type

"hacer" is an -er verb (even though it has stem -changing in other tenses, for present participle of -er verbs, we follow the -er rule here).

Step2: Apply -er verb present participle rule

The stem of "hacer" is "hac", add -iendo.

Answer:

trabajando

2. (beber)