It is better to think of such languages as only having one form of a verb. The verb can be used to indicate the past and future as well as the present. The meaning has to be ascertained form the context, though means of indicating whether the past present or future are referred to are usually available.

It is also important to remember that in a language like English the "tense" of the verb (whether compound or simple) may not necessarily give an indication of the time an action takes place. Thus, in the sentence I am going to London tomorrow the form is present, but the reference is to the future. In I come into the room and find you reading the reference is to the past if you have already come into the the room. Similarly the sentence Every time I open the door I find it's raining can be uttered with meaning even if you are nowhere near a door. So even in English the context is important. Some languages get along fine with a single form of the verb, but often require the speaker to take account of other things which remain unexpressed in English and/or have to be understood from the context.

Marvin A. wrote:

It would be interesting to construct a language that had no verb tenses, and no way of expressing time--such as words like "now", or "then" or "yesterday", etc. If they taught that language to a baby, the baby would have a very different worldview.

You are entering into the realms of the Sapir-Whorf hypothesis! I do not think that even a language without adverbs of time could prevent its speakers from having a concept of time. You would still say things that referred to the past and future.

Hi,

I do not think that even a language without adverbs of time could prevent its speakers from having a concept of time.

My wife has no concept of time. (Cheap joke, rim-shot. And not actually true, in case she reads this.)

Best wishes, Clive