Learn Dutch: Ik zeg één woord.

The infinitive zeggen needs two g's to keep the e short. When divided into syllables (zeg-gen), the first syllable is closed by a consonant, trapping the short "eh" sound. To make the "I" form, we drop the -en, leaving zegg. However, Dutch spelling rules state that a word can never end in a double identical consonant. So, we drop the extra g to get zeg.

Why does the word "één" have accent marks?

The word een without accents is the indefinite article meaning "a" or "an", and it is pronounced with a short, unstressed sound. To mean the number "one", the vowel sound is long. Dutch uses the accent marks (één) to clearly show you mean the specific number, not the article.

The word "woord" sounds like it ends in a 't'. Why is it spelled with a 'd'?

In Dutch, whenever a d is at the very end of a word, it is pronounced like a t. It is spelled with a d because if you make the word plural (woorden), the d moves to the beginning of the next syllable and is pronounced with its normal d sound.