Final answer:
The infinitive stem of "poner" for both the future and conditional tenses in Spanish is "pondr-". This stem is used to conjugate the full verb in these tenses by adding the appropriate endings.
Step-by-step explanation:
The main form of the verb is called the infinitive. The infinitive consists of two parts: the ending and the stem. The ending is the last two letters. There are only three different endings: -ar, -er, and -ir. The stem is everything else, except the ending. The infinitive stem of the verb "poner" in the future and conditional tenses in Spanish is "pondr-".
In these tenses, the infinitive stem changes, and you'll add the respective endings for future and conditional to this stem. For example, yo pondría (I would put) in the conditional, and yo pondré (I will put) in the future tense. The concept of an infinitive phrase in English is to take the base form of a verb, like to put, and use it in different ways within a sentence. It can function as a noun, adverb, or adjective. For instance, “to win” in the sentence 'To win is his goal.' acts as a noun.