Learn Italian: Il robot è nuovo, montalo stasera. - The robot is new, assemble it tonight.

Montalo means 'assemble it'. In Italian, when you give an informal affirmative command (telling someone to do something), you must attach the object pronoun directly to the end of the verb. Here, monta is the informal command for 'assemble', and lo is the pronoun 'it' replacing the masculine noun il robot.

Wait, doesn't the 'tu' form of verbs usually end in '-i'? Why is the command monta?

For regular verbs ending in -are like montare, the informal imperative (the 'tu' command form) actually ends in -a. So, the regular present tense 'you assemble' is tu monti, but the command 'assemble!' is monta!.

Where does the word stasera come from?

Stasera means 'tonight' or 'this evening'. It is simply a shortened, combined version of the phrase questa sera. You will also often see stamattina used for 'this morning'.

How would I make the word robot plural if there were multiple new robots?

Foreign loanwords that end in a consonant, like robot, are almost always masculine in Italian and do not change their spelling in the plural. To say 'the robots', you only change the article, making it i robot