Mistakes Vietnamese speakers make
Vietnamese verbs don't change for tense, person, or number. Time is shown by separate words. Plurals and articles work very differently — so learners must train themselves to add these features in English.
Pick one to practise
Verb tense — no change for past
Vietnamese marks time with separate words ("đã" for past, "sẽ" for future) and keeps the verb unchanged. English changes the verb itself: go → went, eat → ate, see → saw.
Dropping articles
Vietnamese doesn't have articles. English requires "a/an" for first mention of a singular countable noun, and "the" for known specific things.
Missing plural -s
Vietnamese marks plural with separate words ("những", "các") or leaves the noun unchanged. English adds -s to the noun for plurals.
Subject-verb agreement (he / she / it + s)
Vietnamese verbs don't change for the subject. English present simple adds -s for he/she/it: I go, he goes; we eat, she eats.