If you speak Thai, some English grammar rules will feel natural and others will feel confusing. These are the biggest differences to focus on first.
Thai and English both use SVO order, which helps with basic sentences. However, Thai adjectives and relative clauses come after the noun. English adjectives come before the noun — 'a big dog' in English is 'dog big' in Thai.
Thai has no articles. Instead it uses classifiers — specific counting words for different categories of objects. Thai speakers must learn the English article system entirely from scratch.
Thai verbs never change form for tense, person, or number. Time is expressed through separate words. English requires the verb itself to change — a new grammatical habit that takes months to build.