Verb Tense Exercise: Simple Present and Present Continuous

Question

I am answering a verb tense exercise when I came across this:

1. I am currently travelling with Liam, a student from Leeds University in England. He is a nice guy, but impatient. He always walks ahead of me and complains that I am too slow. I (do/ am doing) my best to keep up with him, but he is younger and stronger than I am. Maybe, I am just feeling sorry for myself because I am getting old.

According to the site, the correct answer is "am doing". Please further explain why it is the answer and why "do" isn't.

Another question was this:

2. Right now, Liam is sitting with the owner of the inn. They are discussing the differences between life in England and life in Nepal. I do not know the real name of the owner, but everybody just calls him Tam. Tam speaks English very well and he (tries/is trying) to teach Liam some words in Nepali. Every time Tam says a new word, Liam tries to repeat it. Unfortunately, Liam also seems to have difficulty learning foreign languages. I just hope we don't get lost and have to ask for directions.

According to the site, the correct answer is "is trying". Please further explain why it is the answer and why "tries" isn't.

Answer 1

The action is not permanent but temporary, it is valid for the time of travelling or better, for the time when Liam is walking with him/her; therefore the present progressive is a possibility (ref., see "present vs. progressive tense"). The action in "doing one's best" can be considered to be true in the present time period (the period of travelling with Liam); therefore the simple present is as well a possibility (ref., see "simple present tense, 4).

In conclusion , you can say that neither choice is wrong. Notice that the author does not choose to write "He is always walking ahead of me and complaining that I am too slow.", but instead that he treats Liam's action as "true in the present time period" (the period of travelling with Liam); it is evident that Liam's action can be considered as temporary as well (walking ahead of him only during this period of travelling together); if the choice is free for this action, why not for the other one since they are concommitant?

The explanation for the second question is similar. Note the present simple in "Tam speaks English very well"; the present continuous is not likely here, a different verb would have to be used: " Tam is speaking very well in English.". Nevertheless, if the the author can choose a permanent reference for this first action why couldn't he do so for the other action (tries to teach)? "Tam is trying to teach and Liam tries to repeat" is what we read. Why is it not "Liam is trying to repeat"?