What you're referring to is not a problem of orthography, per se. It is a quality of the English language called "Sandhi"[1], and is fundamental to how we construct grammar.
The fact that Sandhi is often not reflected in our orthography is a mixed blessing. Antai Theesis turning into antithusis would be more phonetically correct but wouldn't preserve the etymology of the combination.
Every language has complexity that seems totally horrible to a foreign learner. German, for example, has three genders, which are to an English speaker completely pointless and annoying. I've yet to study a language that doesn't feel like that, although Spanish is very close to actually making sense: the two genders are 90% a matter of suffix agreement, and the exceptions like "el día" are relatively few and far between.
> Antai Theesis turning into antithusis would be more phonetically correct but wouldn't preserve the etymology of the combination.
The pronounciation of the separate words doesn't preserve their etymologies either. This is my main gripe with (spoken) English: greek and to some extent german words (and probably most other words taken from foreign languages) are completely and randomly mutilated, the result confuses everyone who knows what they mean and how they're pronounced properly.
[1]: http://en.wikipedia.org/wiki/Sandhi
The fact that Sandhi is often not reflected in our orthography is a mixed blessing. Antai Theesis turning into antithusis would be more phonetically correct but wouldn't preserve the etymology of the combination.
Every language has complexity that seems totally horrible to a foreign learner. German, for example, has three genders, which are to an English speaker completely pointless and annoying. I've yet to study a language that doesn't feel like that, although Spanish is very close to actually making sense: the two genders are 90% a matter of suffix agreement, and the exceptions like "el día" are relatively few and far between.