Learn Swedish: Behöver kocken femtio gram salt? - Does the chef need fifty grams of salt?

In Swedish, you do not use a preposition between a measurement and the substance being measured. You just put the two words right next to each other, so it literally translates to 'fifty gram salt'. This is the standard way to express quantities, just like en kopp kaffe (a cup of coffee).

Why does gram look singular when the translation says 'grams'?

It actually is plural here! The word gram is an ett-word (neuter noun) that ends in a consonant. In Swedish, ett-words ending in a consonant look exactly the same in the indefinite plural as they do in the singular. So ett gram is 'one gram', and femtio gram is 'fifty grams'.

Where is the word for 'Does' in this sentence?

Swedish does not use helper verbs like 'do' or 'does' to form questions. Instead, you simply invert the word order by putting the verb first. Starting the sentence with Behöver (needs) followed by the subject kocken (the chef) automatically makes it a yes/no question.

Does kocken refer to anyone who is cooking?

The word en kock usually refers specifically to a professional chef or a cook by trade, with kocken being the definite form ('the chef'). If you are talking about someone just cooking a meal at home, you would typically describe the action using the verb phrase lagar mat (makes food) rather than calling them a chef.