Questions & Answers about Ég var glaður þegar ég sá stelpuna.
Can I use hvenær instead of þegar here since they both mean 'when'?
No, you must use þegar here. Hvenær is a question word used to ask what time something happens. Þegar is a joining word used to connect two parts of a sentence, especially to say that one past event happened at the same time as another.
Why does the adjective glaður end in -ur?
The adjective must match the gender of the subject ég. The ending -ur is the masculine singular form. If the speaker identifying as 'I' were female, the word would change to the feminine form: Ég var glöð.
I don't recognize the verb sá. What is the dictionary form?
Sá is the past tense form of sjá (to see) for ég (I) and hann/hún/það (he/she/it). It is an irregular verb that changes its vowel completely in the past tense instead of just adding a normal past tense ending.
Why is the word for 'the girl' stelpuna instead of stelpan?
Stelpuna is in the accusative case because it is the direct object receiving the action of the verb sjá (to see). The base word stelpa (girl) gets the definite article suffix attached, becoming stelpuna (the girl) in the accusative, while stelpan is the nominative subject form.