Thai is written in its own script — understanding a little makes signs, menus, and taxis far less baffling.
Thai script has 44 consonants, 32 vowels (written above, below, before, and after consonants), and 4 tone marks — it reads left to right.
Numbers are worth recognising on price tags and taxi meters; the words for 'toilet', 'exit', 'entrance' and 'closed' are useful; MRT/BTS signs always have English too.
Google Translate's camera mode reads Thai script in real time — point it at a menu or sign for instant translation; accuracy is good for common words.
Most Bangkok restaurants have English menus or pictures; for places without English, Google Translate camera or pointing at another diner's food works well.